Hi folks,
we often come across certain error response displayed on our browser while trying to access a website, but we really don't know why we got that error or what does that error mean?
So, i have compiled a whole list of Hyper Text Transfer Protocol (HTTP) response codes and reason of that response code being displayed.

The following is a list of Hypertext Transfer Protocol (HTTP) response status codes. This includes codes from IETF internet standards as well as
unstandardized RFCs, other specifications and some additional commonly used codes. The first digit of the status code specifies one of five classes of
response; the bare minimum for an HTTP client is that it recognises these five classes. The phrases used are the standard examples, but any human-readable alternative can be provided. Unless otherwise stated, the statuscode is part of the HTTP/1.1 standard (RFC 2616).
1xx Informational
Request received, continuing process.
This class of status code indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line. Since HTTP/1.0 did not define any 1xx status codes, servers must not send a 1xx response to an HTTP/1.0 client except under experimental conditions.

   100 Continue

This means that the server has received the request headers, and that the client should proceed to send the request body (in the case of a request for which a body needs to be sent; for example, a POST request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the request's headers alone, a client must send Expect: 100-continue as a header in its initial request and check if a 100 Continue status code is received in response before continuing (or receive 417 Expectation Failed and not continue).

   101 Switching Protocols

This means the requester has asked the server to switch protocols and the server is acknowledging that it will do so.

   102 Processing (WebDAV; RFC 2518)

As a WebDAV request may contain many sub-requests involving file operations, it may take a long time to complete the request. This code indicates that the server has received and is processing the request, but no response is available yet. This prevents the client from timing out and assuming the request was lost.This class of status codes indicates the action requested by the client was received, understood, accepted and processed successfully.

   200 OK

Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request the response will contain an entity describing or containing the result of the action.

   201 Created

The request has been fulfilled and resulted in a new resource being created.

   202 Accepted

The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place.

   203 Non-Authoritative Information (since HTTP/1.1)

The server successfully processed the request, but is returning information that may be from another source.

   204 No Content

The server successfully processed the request, but is not returning any content.

   205 Reset Content

The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.

   206 Partial Content

The server is delivering only part of the resource due to a range header sent by the client. The range header is used by tools like wget to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams.

   207 Multi-Status (WebDAV; RFC 4918)

The message body that follows is an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.





208 Already Reported (WebDAV; RFC 5842)
 
    The members of a DAV binding have already been enumerated in a previous reply to this request, and are not being included again.
 
226 IM Used (RFC 3229)
    
The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.[5]

3xx Redirection

The client must take additional action to complete the request.[2]

This class of status code indicates that further action needs to be taken by the user agent to fulfil the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent should not automatically redirect a request more than five times, since such redirections usually indicate an infinite loop.

300 Multiple Choices
    Indicates multiple options for the resource that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation.[2]
301 Moved Permanently
    This and all future requests should be directed to the given URI.[2]
302 Found
    This is an example of industry practice contradicting the standard.[2] The HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"),[6] but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours.[7] However, some Web applications and frameworks use the 302 status code as if it were the 303.[8]
303 See Other (since HTTP/1.1)
    The response to the request can be found under another URI using a GET method. When received in response to a POST (or PUT/DELETE), it should be assumed that the server has received the data and the redirect should be issued with a separate GET message.[2]
304 Not Modified
    Indicates that the resource has not been modified since the version specified by the request headers If-Modified-Since or If-Match.[2] This means that there is no need to retransmit the resource, since the client still has a previously-downloaded copy.
305 Use Proxy (since HTTP/1.1)
    The requested resource is only available through a proxy, whose address is provided in the response.[2] Many HTTP clients (such as Mozilla[9] and Internet Explorer) do not correctly handle responses with this status code, primarily for security reasons.[citation needed]
306 Switch Proxy
    No longer used.[2] Originally meant "Subsequent requests should use the specified proxy."[10]
307 Temporary Redirect (since HTTP/1.1)
    In this case, the request should be repeated with another URI; however, future requests should still use the original URI.[2] In contrast to how 302 was historically implemented, the request method is not allowed to be changed when reissuing the original request. For instance, a POST request should be repeated using another POST request.[11]
308 Permanent Redirect (approved as experimental RFC)[12]
    The request, and all future requests should be repeated using another URI. 307 and 308 (as proposed) parallel the behaviours of 302 and 301, but do not allow the HTTP method to change. So, for example, submitting a form to a permanently redirected resource may continue smoothly.

4xx Client Error

The 4xx class of status code is intended for cases in which the client seems to have erred. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. These status codes are applicable to any request method. User agents should display any included entity to the user.

400 Bad Request
    The request cannot be fulfilled due to bad syntax.[2]
401 Unauthorized
    Similar to 403 Forbidden, but specifically for use when authentication is required and has failed or has not yet been provided.[2] The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. See Basic access authentication and Digest access authentication.
402 Payment Required
    Reserved for future use.[2] The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, but that has not happened, and this code is not usually used. As an example of its use, however, Apple's defunct MobileMe service generated a 402 error if the MobileMe account was delinquent.[citation needed] In addition, YouTube uses this status if a particular IP address has made excessive requests, and requires the person to enter a CAPTCHA.
403 Forbidden
    The request was a valid request, but the server is refusing to respond to it.[2] Unlike a 401 Unauthorized response, authenticating will make no difference.[2] On servers where authentication is required, this commonly means that the provided credentials were successfully authenticated but that the credentials still do not grant the client permission to access the resource (e.g. a recognized user attempting to access restricted content).
404 Not Found
    The requested resource could not be found but may be available again in the future.[2] Subsequent requests by the client are permissible.
405 Method Not Allowed
    A request was made of a resource using a request method not supported by that resource;[2] for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.
406 Not Acceptable
    The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.[2]
407 Proxy Authentication Required
    The client must first authenticate itself with the proxy.[2]
408 Request Timeout
    The server timed out waiting for the request.[2] According to W3 HTTP specifications: "The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time."
409 Conflict
    Indicates that the request could not be processed because of conflict in the request, such as an edit conflict.[2]
410 Gone
    Indicates that the resource requested is no longer available and will not be available again.[2] This should be used when a resource has been intentionally removed and the resource should be purged. Upon receiving a 410 status code, the client should not request the resource again in the future. Clients such as search engines should remove the resource from their indices. Most use cases do not require clients and search engines to purge the resource, and a "404 Not Found" may be used instead.
411 Length Required
    The request did not specify the length of its content, which is required by the requested resource.[2]
412 Precondition Failed
    The server does not meet one of the preconditions that the requester put on the request.[2]
413 Request Entity Too Large
    The request is larger than the server is willing or able to process.[2]
414 Request-URI Too Long
    The URI provided was too long for the server to process.[2]
415 Unsupported Media Type
    The request entity has a media type which the server or resource does not support.[2] For example, the client uploads an image as image/svg+xml, but the server requires that images use a different format.
416 Requested Range Not Satisfiable
    The client has asked for a portion of the file, but the server cannot supply that portion.[2] For example, if the client asked for a part of the file that lies beyond the end of the file.[2]
417 Expectation Failed
    The server cannot meet the requirements of the Expect request-header field.[2]
418 I'm a teapot (RFC 2324)
    This code was defined in 1998 as one of the traditional IETF April Fools' jokes, in RFC 2324, Hyper Text Coffee Pot Control Protocol, and is not expected to be implemented by actual HTTP servers.
419 Authentication Timeout
    Not a part of the HTTP standard, 419 Authentication Timeout denotes that previously valid authentication has expired. It is used as an alternative to 401 Unauthorized in order to differentiate from otherwise authenticated clients being denied access to specific server resources.
420 Enhance Your Calm (Twitter)
    Not part of the HTTP standard, but returned by the Twitter Search and Trends API when the client is being rate limited.[13] Other services may wish to implement the 429 Too Many Requests response code instead.
422 Unprocessable Entity (WebDAV; RFC 4918)
    The request was well-formed but was unable to be followed due to semantic errors.[4]
423 Locked (WebDAV; RFC 4918)
    The resource that is being accessed is locked.[4]
424 Failed Dependency (WebDAV; RFC 4918)
    The request failed due to failure of a previous request (e.g. a PROPPATCH).[4]
424 Method Failure (WebDAV)[14]
    Indicates the method was not executed on a particular resource within its scope because some part of the method's execution failed causing the entire method to be aborted.

425 Unordered Collection (Internet draft)
    Defined in drafts of "WebDAV Advanced Collections Protocol",[15] but not present in "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol".[16]
426 Upgrade Required (RFC 2817)
    The client should switch to a different protocol such as TLS/1.0.[17]
428 Precondition Required (RFC 6585)
    The origin server requires the request to be conditional. Intended to prevent "the 'lost update' problem, where a client GETs a resource's state, modifies it, and PUTs it back to the server, when meanwhile a third party has modified the state on the server, leading to a conflict."[18]
429 Too Many Requests (RFC 6585)
    The user has sent too many requests in a given amount of time. Intended for use with rate limiting schemes.[18]
431 Request Header Fields Too Large (RFC 6585)
    The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large.[18]
444 No Response (Nginx)
    Used in Nginx logs to indicate that the server has returned no information to the client and closed the connection (useful as a deterrent for malware).
449 Retry With (Microsoft)
    A Microsoft extension. The request should be retried after performing the appropriate action.[19]
    Often search-engines or custom applications will ignore required parameters. Where no default action is appropriate, the Aviongoo website sends a "HTTP/1.1 449 Retry with valid parameters: param1, param2, . . ." response. The applications may choose to learn, or not.
450 Blocked by Windows Parental Controls (Microsoft)
    A Microsoft extension. This error is given when Windows Parental Controls are turned on and are blocking access to the given webpage.[20]
451 Unavailable For Legal Reasons (Internet draft)
    Defined in the internet draft "A New HTTP Status Code for Legally-restricted Resources".[21] Intended to be used when resource access is denied for legal reasons, e.g. censorship or government-mandated blocked access. A reference to the 1953 dystopian novel Fahrenheit 451, where books are outlawed.[22]
451 Redirect (Microsoft)
    Used in Exchange ActiveSync if there either is a more efficient server to use or the server can't access the users' mailbox.[23]
    The client is supposed to re-run the HTTP Autodiscovery protocol to find a better suited server.[24]
494 Request Header Too Large (Nginx)
    Nginx internal code similar to 413 but it was introduced earlier.[25][original research?]
495 Cert Error (Nginx)
    Nginx internal code used when SSL client certificate error occurred to distinguish it from 4XX in a log and an error page redirection.
496 No Cert (Nginx)
    Nginx internal code used when client didn't provide certificate to distinguish it from 4XX in a log and an error page redirection.
497 HTTP to HTTPS (Nginx)
    Nginx internal code used for the plain HTTP requests that are sent to HTTPS port to distinguish it from 4XX in a log and an error page redirection.
499 Client Closed Request (Nginx)
    Used in Nginx logs to indicate when the connection has been closed by client while the server is still processing its request, making server unable to send a status code back.[26]

5xx Server Error

The server failed to fulfill an apparently valid request.[2]

Response status codes beginning with the digit "5" indicate cases in which the server is aware that it has encountered an error or is otherwise incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and indicate whether it is a temporary or permanent condition. Likewise, user agents should display any included entity to the user. These response codes are applicable to any request method.

500 Internal Server Error
    A generic error message, given when no more specific message is suitable.[2]
501 Not Implemented
    The server either does not recognize the request method, or it lacks the ability to fulfil the request.[2]
502 Bad Gateway
    The server was acting as a gateway or proxy and received an invalid response from the upstream server.[2]
503 Service Unavailable
    The server is currently unavailable (because it is overloaded or down for maintenance).[2] Generally, this is a temporary state.
504 Gateway Timeout
    The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.[2]
505 HTTP Version Not Supported
    The server does not support the HTTP protocol version used in the request.[2]
506 Variant Also Negotiates (RFC 2295)
    Transparent content negotiation for the request results in a circular reference.[27]
507 Insufficient Storage (WebDAV; RFC 4918)
    The server is unable to store the representation needed to complete the request.[4]
508 Loop Detected (WebDAV; RFC 5842)
    The server detected an infinite loop while processing the request (sent in lieu of 208).
509 Bandwidth Limit Exceeded (Apache bw/limited extension)
    This status code, while used by many servers, is not specified in any RFCs.
510 Not Extended (RFC 2774)
    Further extensions to the request are required for the server to fulfil it.[28]
511 Network Authentication Required (RFC 6585)
    The client needs to authenticate to gain network access. Intended for use by intercepting proxies used to control access to the network (e.g. "captive portals" used to require agreement to Terms of Service before granting full Internet access via a Wi-Fi hotspot).[18]
598 Network read timeout error (Unknown)
    This status code is not specified in any RFCs, but is used by Microsoft HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.[citation needed]
599 Network connect timeout error (Unknown)
    This status code is not specified in any RFCs, but is used by Microsoft HTTP proxies to signal a network connect timeout behind the proxy to a client in front of the proxy.

Hi folks,
 Here I m with trick to install and run Vlc media player as root in Backtrack.
Normally in backtrack  you cant run vlc as root but by using this trick its possible.

First we need to install vlc media player

open terminal at hash prompt type this command

 for root users

# apt-get install vlc

for non root users

# sudo apt-get install vlc

you will be prompted whether to continue or not, be wise and press y

now w8 for few seconds depending upon your internet speed.

after completion of this command you will be returned to hash prompt,

to check whether it is running or not type vlc at hash prompt

# vlc

for non-root user it will work but for root user it will return an error message

"VLC is not supposed to be run as root. Sorry.
If you need to use real-time priorities and/or privileged TCP ports
you can use vlc-wrapper (make sure it is Set-UID root and
cannot be run by non-trusted users first)."


now no need to panic we can resolve this problem with a simple hack

all we need to to do is to open /usr/bin/vlc in any text editor like vi or vim

 # vim /usr/bin/vlc

now at this point search geteuid and replace it with getppid

at editor press ctrl+shift+f and type geteuid

now click on geteuid press insert key and replace geteuid with getppid

press esc key and then type

:wq and press enter

its all done

now check whether vlc is working or not just type vlc at hash prompt

# vlc
and you can see vlc media player comes up....

Hi folks,
Often we come across this word Encryption, and then number of questions starts to arise like, what does this word encryption refer to?, How does it works?  well now I m going to discuss these things here with you...



First thing that we need to know is What is Encryption?
  Encryption is the process of transforming Information (plain text) to unreadable hash using an algorithm called Cipher. and the reverse process that is to make the encrypted data readable again, is called Decryption.  In more practical terms, the encryption methods apply a certain routine to information so that it’s no longer recognizable as it’s original. With the right key, that was determined before encrypting the data and the accompanying routine for decrypting the information, the original information can be recovered.
Cryptography was first pioneered many centuries ago. It was the work of specialists to create encryption routines for the military mainly. Cryptography remained something mainly for the military for quite long. Up until a century ago almost entirely and only in the last 20 to 30 years has it become mainstream. Nowadays it’s being used all around us; in ATM cards, on e-commerce websites, in game consoles, for the distribution of copyrighted music and film and many more applications. This is all possible due to the rise of the computer and readily available gross amounts of computing power. Considering the computing power available nowadays we’re actually encrypting very little and leaving the door right open to a lot of sensitive data.

Why do we need to encryption more?
If you don’t all ready know it, without encryption there is no such thing as privacy. At least not for your data. It’s all 1′s and 0′s but doesn’t take a genius at all to recognize the data it represents if it’s not encrypted when intercepted. And there are literally thousands of ways to intercept data, but I’ll list some common ways.

• Internet
  is probably the most dangerous place for your data as concerned with privacy. If you don’t use a encrypted connection with the server, pretty much anybody can get their hands on your full communication. People in your local network, your internet provider, the host of the web-site you’re visiting, proxies you’re tunnelled through even if they are transparent and you don’t even notice or know, any carrier of your traffic which can be pretty much any arbitrary person for all you know because routes are chosen dynamically and you have very little to no influence on that and last but not least someone who specifically targets your communication being either a hacker, the government or who knows who.
• E-mail
  is pretty much the same story as for internet
• Instant messaging
  is also just as weak as the whole rest of the internet!
• WiFi
  is a special case all by itself. Special for the fact that it’s extremely dangerous. This is because the information is just put straight into the air for anybody to receive. With the right antenna this can even be from quite far away. Further away than you can be from the access point. Can you imagine what happens if this is unencrypted, or encrypted with some weak encryption such as wep?
• USB-sticks
  might get stolen or lost. Just plug ‘m in, thanks to plug ‘n play, no problem. The average grandmother can do that. Even encrypted and supposedly safe USB sticks might very well turn out to be very insecure after all.
• External hard drives
  as you might have figured suffer from pretty much the same issues as USB-sticks except for that less of them are out there who actually try and protect your data.
• Personal Computers
  get stolen. But a bigger risk might be that other people use them as well. Maybe you don’t fear your husband, wife or maybe even the kids wandering around through your computer, but what about the friends and family who visit your house. Maybe even friends of friends during a party? And did you ever think about the possibility that you might ever become under criminal or tax fraud investigation. You don’t even have to be guilty to be investigated, that’s the ‘beauty’. But then you say, I’ve got my account protected with a password and I’ve made my files private, isn’t that enough? NO! Plain simple NO! All though it will prevent the occasional access to your files it won’t stop the more determent of mind. If they have full access to the hardware, e.g. stolen computer or you’re under investigation, then it’s very easy, but even with limited access it’s possible. Some years ago at a institution we were able to retrieve a very sophisticated password from a machine with a padlock on the case, the HDD as only boot device and bios password set. And then there still is the malware that endangers your data.
• Laptops
  are the same as PC’s except for that they are stolen much easier, more often, get in the range of different people more easily and that customs have the right to search them if you travel abroad.
Encrypting more, doesn’t that sound like a wise decision?
 
 

Hey folks,
  Often we set Password at the BIOS to secure our systems delicate CMOS setting, but due rare use of bios password we tend to forget it. and got stucked at the time when we need  some alteration in the CMOS. If its desktop its easy to crack it by simply removing the cmos battery few seconds and then putting it down. But What in case of laptop?
No need to worry at all I have the solution for that just follow these steps and your Bios password will be vanished.
First thing you need to do is open up a Command Prompt window

At command prompt type debug

      Hi folks, it become very irritating when a software that we use expires every 30 days and to reinstall it we have to format our system, which takes a lot of our valuable time. But now no need to worry any more coz i m here with the solution. Now you can use the same installed winrar for as long as you wish that too without help of any third party software.
Now to crack winrar just follow these steps...

Step 1
Open a notepad and paste below code in it-
RAR registration da...ta
WinRAR
Unlimited Company License
UID=4b914fb772c8376bf571
6412212250f5711ad072cf351cfa39e2851192daf8a362681bbb1d
cd48da1d14d995f0bbf960fce6cb5ffde62890079861be57638717
7131ced835ed65cc743d9777f2ea71a8e32c7e593cf66794343565
b41bcf56929486b8bcdac33d50ecf773996052598f1f556defffbd
982fbe71e93df6b6346c37a3890f3c7edc65d7f5455470d13d1190
6e6fb824bcf25f155547b5fc41901ad58c0992f570be1cf5608ba9
aef69d48c864bcd72d15163897773d314187f6a9af350808719796

Step 2
save the file as it is with the filename - "rarreg.key"

Step 3
Now cut this file from Desktop and paste it in
"C:\Program Files\WinRAR"
IF A WINDOW WILL POP UP SHOWING "FILE ALREADY THERE"
Then use common sense :) and click on  "Yes, I want to replace"

Step 4
Click on WinRAR.exe and click on Help and select About.....there u go ...the 
Product is Licenced 

  Now enjoy the carcked version of Winrar..

Hey folks,
        Your computer fallen sick? Need intense care? and you can't find it how to solve... No problem here comes the Expert, the SlimCleaner. small yet powerful utility that helps fix your computer problems more easily and efficiently.

SlimCleaner uses what's called "authoritative ranking" to ensure that the ratings for your programs are accurate and that they reflect what people really think. It works by weighing the ratings of each contributor against their previous levels of accuracy and against the ratings of high-ranking users.

SlimCleaner  has further more exciting features, It has got Cleaner, Optimizer, Uninstaller, Shredder, Hijack Log, and most important it has got direct access to windows services like defragger, device manager, etc...
Apart from all these this utility comes free of cost you can easily download it from here, Just click on download button and you are done.

Hi folks,
Many times we gets messed up with one or the other abbriviations, due to this small use of abbriviations we fails to understand the whole line or para written in computer books or any other such sources. So I have collected all these abbreviations together and shared with you all... And yes I might have missed out some but then not an issue if you cant find any specific one please le me know about it via comments, and i will provide you with its fullform within 24hrs of your comment.

A
A-D         Analog to Digital
AA          Author's Alteration
AA          Auto Answer
AAL5        ATM Adaption Layer 5
ABEND       Abnormal End
ABI         Application Binary Interface
ABR         Available Bit Rate
AC97        Audio Codec 97
ACB         Access method Control Block
ACDS        Active Control Data Set
ACE         Asynchronous Communications Element
ACF         Advanced Communication Facility
ACIA        Asynchronous Communications Interface Adapter
ACK         Acknowledge
ACS         Asynchronous Connection Server
ACS         Automatic Class Selection
ACSE        Application Control Service Element
ACT         Application Control Table
ACU         Automatic Calling Unit
ADC         Analog Digital Converter
ADDMD       Administrative Directory Management Domain
ADMD        Administrative Management Domain
ADO         ActiveX Data Object
ADSL        Asymetric Digital Subscriber Line
AEA         Activity End Acknowledge
AEI         Application Entity Invocation
AF          Application Framework
AFP         Advanced Function Printing
AGP         Accellerated Graphics Port
AGS         Advanced Graphics System
AI          Artificial Intelligence
AIU         Application Interface Unit
AIX         Advanced Interactive eXecutive
AIX         Alternate IndeX
ALGOL       ALGOrithmic Language
ALI         Acer Labs, Incorporated
ALS         Application Layer Structure
ALS         Automatic Line Switching
ALT         Application Load Table
ALU         Arithmetic and Logic Unit
AM          Access Method
AMD         Advanced Micro Devices
AMH         Automated Material Handling
AMI         Alternate Mark Inversion
AMIS        Audio Messaging Interchange Specification
AMR         Audio Modem Riser
AMS         Access Method Services
ANR         Automatic Network Routing
ANS         Advanced Network Services
ANSI        American National Standards Institute
AOCE        Apple Open Collaboration Environment
AOW         Asian and Oceanic Workshop for open systems
AP          Access Point
AP          Automation Protocol
APA         All Points Addressable
APC         American Power Conversion
APDU        Application Protocol Data Unit
API         Application Programming Interface
APIA        API Association
APL         A Programming Language
APPC        Advanced Program-to-Program Communication
APPI        Advanced Peer-to-Peer Internetwork(ing)
APPN        Advanced Peer-to-Peer Network(ing)
APS         Advanced Production System
AR          Attention Routine
ARP         Address Resolution Protocol
ARPA        Advanced Research Projects Agency
ARPANET     Advanced Research Projects Agency Network
ARU         Audio Response Unit
AS          Activity Start
AS          Autonomous System
ASC         Accredited Standards Committee
ASCII       American Standard Code for Information Interchange
ASE         Application Service Element
ASIC        Application-Specific Integrated Circuit
ASN         Abstract Syntax Notation
ASN.1       Abstract Syntax Notation One
ASO         Application Service Object
ASP         Active Server Pages
ASIC        Advanced SCSI Programming Interface
ASR         Automatic Speech Recognition
ASTs        Asynchronous System Traps
AT          Advanced Technology
ATI         ATI Technologies Inc.
ATM         Adobe Type Manager
ATM         Asynchronous Transfer Mode
ATM         Automatic Teller Machine
ATMP        Ascend Tunnel Management Protocol
ATSF        Alert Transport Service Facility
ATX         Advanced Technology eXtended
AU          Access Unit
AVR         Automatic Volume Recognition
AWG         American Wire Gauge

B
B8ZS        Binary Eight Zero Substitution
BABT        British Approvals Board for Telecommunications
BAL         Business Application Language
BAM         Basic Access Methods
BAS         Basic Activity Subset
BASH        Bourne-Again SHell
BASIC       Beginners All-Purpose Symbolic Instruktion Code
BBS         Bulletin Board System
BCC         Block Check Character
BCD         Binary Coded Decimal
BCF         Bridge Control Facility
BCPL        Basic Combined Programming Language
BCS         Basic Catalog Structure
BCS         Basic Combined Subset
BDAM        Basic Direct Access Method
BDR         Basic Density Range
BEL         Bell
BER         Bit Error Rate
BES         Bursty Errored Seconds
BG          BackGround
BHT         Branch History Table
BIOS        Basic Input/Output System
BIS         Business Information System
BISYNC      Binary Synchronous Communication
BIT         Binary Digit
BITNIC      Bitnet Network Information Center
BLOB        Binary Large Object
BMIC        Bus Master Interface Controller
BMP         BitMaP
BMS         Basic Mapping Support
BNC         Barrel Nut Connector
BNN         Boundary Network Node
BOC         Bell Operating Companies
BOT         Begin Of Tape
BP          Base Pointer
BPAM        Basic Partitioned Access Method
BPI         Bytes Per Inch
BPS         Bites Per Second
BRA         Basic Rate Access
BRI         Basic Rate Interface
BS          Backspace / British Standard
BSA         Basic Service Area
BSAM        Basic Sequential Access Method
BSC         Binary Synchronous Communication
BSD         Berkeley Software Distribution
BSDS        BootStrap Data Set
BSI         British Standards Institute
BSS         Basic Synchronous Subset
BTAC        Branch Target Address Cache
BTAM        Basic Teleprocessing Access Method
BTA-ES      Basic Teleprocessing Access Method - Extended Storage
BYP         Bypass

C
CA          Collision Avoidance
CA...       Computer Aided ...
CAA         Computer Aided Architecture
CAD         Computer Aided Design
CADD        Computer Aided Design and Drafting
CADIS       Computer Aided Design Interactive System
CAE         Common Application Environment
CAE         Computer Assisted Education, Computer Aided Engineering = CAD             + CAP + CAQ
CAH         Computer Aided Handling
CAI         Computer Aided Instruction = CIM + CAO
CAISE       Computer Aided Integrated Software Engineering
CALS        Computer Aided Acquisition and Logistic Support
CAM         Computer Aided Manufacturing / Content Adressable Memory
CAMAC       Computer Automated MeAsurement Control
CAN         Cancel
CAO         Computer Aided Office
CAP         Computer Aided Planning / Computer Aided Publishing
CAPP        Computer Aided Production Planning
CAPPC       Computer Aided Production Planning and Control
CAPSC       Computer Aided Production Scheduling and Control
CAQ         Computer Aided Quality Assurance
CAR         Computer Aided Roboting
CAR         Computer Assisted Radiology
CAS         Computer Aided Selling
CASE        Common Application Service Elements
CASE        Computer Aided Software-Engineering
CAT         Computer Aided Testing
CATV        CAble TeleVision
CBDS        Connectionless Broadband Data Service
CBEMA       Computer and Business Equipment Manufacturers' Association
CBR         Constant Bit Rate
CBT         Computer Based Training
CCD         Charge-Coupled Device
CCETT       Centre Commun d'Etudes de Telediffusion et Telecommunications
CCIR        International Radio Consultative Committee
CCITT       Comite Consultatif International Telegraphique et Telephonique
CCR         Committment, Concurrency and Recovery
CCS         Common Communication Support
CCTA        Central Computer and Telecommunications Agency
CCU         Communication Control Unit
CCW         Channel Command Word
CD          Collision Detection
CD          Compact Disk
CDB         Command Descriptor Block
CDC         Century Date Change
CDDA        Compact Disk - Digital Audio
CDDI        Copper Data Distribution Interface
CDE         Common Desktop Environment
CDG         Compact Disk - Graphic
CDI         Compact Disk Interactive
CDMA        Code Division Multiple Access
CDPD        Cellular Digital Packet Data
CDR         Copy Density Range
CDROM       Compact Disk ROM
CDTV        Commodore Total Vision
CDXA        Copmact Disk eXtended Architecture
CEC         Commission of European Communities
CEFIC       Conseil Européen des Federations de l'Industrie Chimique
CELP        Code Excited Linear Prediction
CEN         Comité Européen de Normalisation
CENELEC     Comité Européen de Normalisation Electrotechnique
CEO         Comprehensive Electronic Office
CEPT        Conference Européenne des Administrations des Postes et
            des Telecommunications
CERN        Conseil Européen pour la Recherche Nucléaire
CF          Call Forwarding
CF          Carry Flag
CF          Control Function
CFV         Call For Votes
CGA         Colour Graphics Adapter
CGI         Common Gateway Interface
CGI         Computer Graphics Interface
CGM         Computer Graphics Metafile
CHAP        Challenge-Handshake Authentication Protocol
CHL-I       CHanneL Interface
CHPID       CHannel Path IDentifier
CI          Computer Interconnect
CI          Control Interval
CIAM        Computer Integrated and Automated Manufacturing
CIB         Computer Integrated Business
CICS        Customer Information Control System
CID         Configuration, Installation and Distribution
CIF         Cells In Frames
CIF         Common Intermediate Format
CIF         Computer Integrated Factory = CIO + CIM
CIM         Computer Input by Microfilm
CIM         Computer Integrated Manufacturing = PPS + CAE + CAM
CIO         Computer Integrated Office
CIR         Committed Information Rate
CIS         Card Information Structure
CISC        Complex (Complete) Instruction Set Computer
CIT         Computer Integrated Telephony
CIV         Conversation Verb Interface
CKD         Count Key Data
CL          Core Image Library
CL          Connectionless 
CLI         Call Level Interface
CLIM        Compaq/Lotus/Intel/Microsoft
CLNS        Connectionless Network Service
CM/2        Communication Manager / 2
CMC         Communication Management Configuration
CMEA        Council for Mutual Economic Assistance
CMIP        Common Management Information Protocol
CMIS        Common Management Information Service
CMOS        Cellular Management Operation System
CMOS        Complimentary Metal Oxide Semiconductor
CMOT        Common Management Information Protocol (CMOT) Over TCP/IP
CMR         Communications Resource Manager
CMS         Conversational Monitor System
CMYK        Cyan, Magenta, Yellow, Black
CN          Corporate Network
CNC         Computerized Numerical Control
CNLP        Connectionless Network Protocol
CNM         Communication Network Management
CNMA        Communication Network for Manufacturing Applications
CNR         Carrier-to-Noise-Ratio
COBOL       COmmon Business Oriented Language
COCOM       Coordinating Comittee on Multilateral Export Controls
CODASYL     COnference on DAta SYstems Languages
Codec       Coder/Decoder
COFF        Common Object File Format
COM         Common Object Model
COM         Computer Output on Microfilm
COMAL       COMmon Algorithmic Language
COMREG      Communication Region
CONS        Connection-Oriented Network Service
CORBA       Common Object Request Broker Architecture
COS         Corporation for Open Systems
COSE        Common Open Software Environment
COSINE      Cooperation for OSI Networking in Europe
COSS        Cross Operating System Service
CP          Control Program
CP-SVR      Control Point to Server
CP/M        Control Program/Monitor (for Microcomputer)
CPE         Customer Premises Equipment
CPI         Characters Per Inch
CPI         Common Programming Interface
CPI         Computer to PABX Interface
CPIC        Common Programming Interface for Communications
CPL         Current Privilege Level
CPR         Computerized Patient Record
CPS         Characters Per Second
CPU         Central Processing Unit
CR          Carriage Return
CR          Communication Region
CRC         Cyclic Redundancy Check
CRJE        Conversational Remote Job Entry
CRS         Computer Reservation System
CRS         Configuration Report Server
CRT         Cathode Ray Tube
CS          Communications Server
CSA         Common System Area
CSC         Cross System Consistency
CSDN        Circuit Switched Data Network
CSECT       Control Section
CSI         Consolidated Software Inventory
CSLIP       Compressed SLIP
CSMA/CA     Carrier Sense Multiple Access with Collision Avoidance
CSMA/CD     Carrier Sense Multiple Access with Collision Detection
CSP         Control Sequence Prefix
CSP         Cross System Product
CSPDN       Circuit Switched Public Data Network
CSS         Cascading Style Sheet
CST         Computer Supported Telephony
CSU         Channel Service Unit
CSU/DSU     Channel Service Unit / Data Service Unit
CT          Continuous Tone
CT2T        Continuous Tone To Tape
CTC         Channel To Channel
CTC         CICS To CICS
CTS         Clear To Send
CTS         Conformance Test System
CTS-WAN     Conformance Testing Services for WAN
CU          Control Unit
CUA         Common User Access
CUT         Control Unit Terminal
CVOL        Control VOLume
CWS         Coalition for Working Systems

D
D/A         Digital/Analog
DA          Desk Accessory
DAC         Digital Analog Converter
DAC         Dual Attachment Concentrator
DAI         Distributed Artificial Intelligence
DAM         Direct Access Method 
DAP         Directory Access Protocol
DAP         Document Application Profile
DARPA       Defense Advanced Research Projects Agency
DAS         Dual Attachment Station
DASD        Direct Access Storage Device
DAT         Digital Audio Tape
DAT         Dynamic Address Translation
DB          Database
DBCS        Double Byte Character Set
DBMS        DataBase Management System
DBRT        Directed Beam Refresh Terminal
DC          Data Cartridge
DC          Data Communication
DCA         Document Content Architecture
DCAF        Distributed Console Access Facility
DCB         Data Control Block
DCB         Disk Coprocessor Board
DCC         Diskette Controller Chip
DCE         Data Circuit terminating Equipment
DCE         Data Communications Equipment
DCE         Distributed Computing Environment
DCI         Display Control Interface
DCL         Digital Command Language
DCS         Desktop Color Separation
DCT         Destination Control Table
DCT         Discrete Cosine Transform
DD          Data Definition
DDCMP       Digital Data Communications Message Protocol
DDCS        Distributed Database Connecion Services/2
DDE         Dynamic Data Exchange
DDES        Digital Data Exchange Specifications
DDI         Device Driver Interface
DDK         Driver Development Kit
DDL         Data Definition Language
DDL         Document Description Language
DDM         Distributed Data Management
DDN         Defense Data Network
DDP         Distributed Data Processing
DDRM        Device driver interface/Driver kernel interface
            Reference Manual
DDS         Dataphone Digital Service 
DDS         Decision Support System
DECT        Digital European Cordless Telephone
DECUS       Digital Equipment Computer Users Society
DEL         Delete
DES         Data Encryption Standard
DF          Direction Flag
DFC         Distributed Coordination Function
DFDSS       Data Facility Data Set Services
DFHSM       Data Facility Hierarchical Storage Manager
DFP         Data Facility Product
DFR         Document Filing and Retrival
DFS         Distributed File System
DFSMS       Data Facility Storage Management Subsystem
DFSORT      Data Facility Sort
DFT         Distributed Function Terminal
DFWMAC      Distributed Foundation Wireless Media Access Control
DHCP        Dynamic Host Configuration Protocol
DHTML       Dynamic HTML
DIA         Document Interchange Architecture
DIB         Data Input Bus
DIB         Device Independent Bitmap
DIFS        Distributed coordination function InterFrame Space
DIMM        Dual Inline Memory Module
DIP         Dual Inline Package
DIS         Draft International Standard
DISSOS      Distributed Office Support System
DIT         Directory Information Tree
DKI         Driver Kernel Interface
DL          Data Length
DL          Directory Listing
DL/1        Data Language 1
DLBL        Disk Label
DLCI        Data Linc Connection Identifier
DLE         Data Link Escape
DLL         Dynamic Link Library
DLS         Device Level Selection
DLSE        Device Level Selection Enhanced
DLSw        Data Link Switching
DLUR        Dependent LU Requester
DLUR/S      Dependent LU Requester / Server
DLUS        Dependent LU Server
DMA         Direct Memory Access
DMCI        Direct Memory Communications Interface
DMD         Directory Management Domain
DMI         Digital Multiplexed Interface
DML         Data(base) Manipulation Language
DMNL        Direct Multi Network Link
DMP         Dot Matrix Printer
DN          Distinguished Name
DNA         Digital Network Architecture
DNS         Domain Name Service
DOC         Display Operator Console
DOE         Distributed Objects Everywhere
DOMF        Distributed Object Management Facility
DOS         Declaration Of Support
DOS         Disk Operating System
DOS/VS      Disk Operating System / Virtual Storage
DOS/VSE     Disk Operating System / Virtual Storage Extended
DP          Data Processing
DP          Draft Proposal
DPA         Document Printing Application
DPF         Data Private Facility
DPI         Dots Per Inch
DPL         Descriptor Privilege Level
DPMS        Display Power Management Signaling
DPS         Dynamic Path Selection
DQDB        Distributed Queue Dual Bus
DRAM        Dynamic Random Access Memory
DRQ         Data ReQuest
DS          Digit Select
DS          Directory System
DSA         Directory System Agent
DSA         Distributed Systems Architecture
DSA         Dynamic Storage Area
DSF         Device Support Facility
DSL         Direct Swift Link
DSN         DataSetName
DSN         Distributed Systems Network
DSNL        Direct Swift Network Link
DSOM        Distributed System Object Model
DSP         Digital Signal Processor
DSP         Directory System Protocol
DSR         Data Set Ready
DSSI        Digital Storage Systems Interconnect
DSU         Data Service Unit
DTAM        Document Transfer, Access and Manipulation
DTD         Document Type Definition
DTE         Data Terminal Equipment
DTI         Department of Trade and Industry (UK)
DTP         DeskTop Publishing
DTR         Data Terminal Ready
DU          Data Unit
DUA         Directory User Agent
DUN         Dispatch Unit Number
DVI         Digital Video Interface
DVST        Direct View Bistable Storage
DXI         Data eXchange Interface

E
E1          2,048 Mbps
E3          34 Mbps
EARN        European Academic and Research Network
EB          Error Bell
EB          ExaByte (1,152,921,504,606846,976 bytes)
EBAM        Electronic Beam-Addressable Memory
EBCD        Extended Binary Coded Decimal
EBCDIC      Extended Binary Coded Decimal Interchange Code
ECC         Error Checking and Correction
ECC         Error Correction Code
ECE         Economic Commission for Europe
ECF         Enhanced Connectivity Facility
ECITC       European Committee fo IT Testing and Certification
ECKD        Extended Count-Key Data
ECMA        European Computer Manufacturers Association
ECTUA       European Counsil for Telecommunications Users Association
EDC         Enterprise Database Connectivity
EDF         Execution Diagnostic Facility
EDG         Electronic Dot Generation
EDI         Electronic Data Interchange
EDICON      EDI Community for the Construction Industry (UK)
EDIF        Electronic Design Interchange Format
EDIFACT     Electronic Data Interchange For Administration, Commerce and
            Transport
EDIM        Electronic Data Interchange Message
EDIMS       EDI Messaging System
EDM         Engineering Data Management
EDP         Electronic Data Processing
EDR         Early Device Release
EEMA        European Electronic Mail Association
EFT         Electronic Funds Transfer
EGA         Enhanced Graphics Adapter
EGP         Exterior Gateway Protocol
EHLLAPI     Emulator High Level Language Applications Programming Interface
EIB         Execute Interface Block
EIP         Execute Interface Program
EISA        Extended Industry Standard Architecture
EIT         Encoding Information Type
EIUF        European ISDN User Forum
ELAN        European LAN
ELAN        Extended LAN
ELAN        Emulated LAN
EM          End of Medium
EMA         Enterprise Management Architecture
EMS         Expanded Memory Specification
EMUG        European MAP Users Group
EN          European Norme
ENE         Enterprise Network Event
ENP         Enable Presentation
ENQ         Enquiry
EO          Eight Ones
EOB         End of Block
EOC         End of Cylinder
EOF         End of File
EOJ         End of Job
EOP         End of Procedure
EOT         End of Transmission
EOV         End of Volume
EP          Emulation Program
EPDE        Electronic Product Data Exchange
EPOW        Emergency Power Off Warning
EPROM       Eraseable Programable Read Only Memory
EPS         Encapsulated PostScript
EPSF        Encapsulated PostScript Format
ER          Entity Relationship
ERDS        Error Recording Data Set
EREP        Environmental Record Editing and Printing program
ES          Errored Second
ESA         Extended Service Area
ESC         Escape
ESCON       Enterprise System Connection Architecture
ESD         Electronic Software Distribution
ESD         External Symbol Dictionary
ESDI        Enhanced Small Device Interface
ESDS        Entry Sequenced Data Set
ESF         Extended SuperFrame
ESPRIT      European Strategic Programme for Research and development in
            Information Technology
ESQA        Extended System Queue Area
ETB         End of Transmission Block
ETCOM       European Testing and Certification for Office and
            Manufacturing protocols
ETS         European Telecommunication Standard
ETSI        European Telecommunication Standards Institute
ETX         End of Text
EUnet       European Unix Network
EUUG        European Unix User Group
EVI         EVent Information
EWOS        European Workshop for Open Systems
EXCP        EXecute Channel Program
EZ          Excessive Zeros

F
F/STP       Foil STP
FA          Foreign Agent
FAQ         Frequently Asked Questions
FAST        Federation Against Software Theft
FAT         File Allocation Table
FBA         Fix Block Architecture
FBA         Fixed Blocked ANSI-defined printer control characters
FBM         Fix Block Modus
FC          File Control
FCB         Format Control Buffer
FCP         File Control Program
FCS         Frame-Check Sequence
FCT         File Control Table
FDD         Fixed Disk Drive
FDDI        Fiber Distributed Data Interface
FEAL        Fast Data Encipherment Algorithm
FEP         Front-End Processor
FF          Formfeed
FH          Frame Handler
FIFO        First In, First Out
FIPS        Federal Information Processing Standard
FLOPS       Floating-point operations per second
FMLI        Forms and Menu Language Interpreter
FOB         Form Overlay Buffer
FOND        Font family descriptor
FORTRAN     FORmula TRANslator
FPU         Floating Point Unit
FRAD        Frame Relay Access Device
FROM        Factory ROM
FRU         Field Replaceable Unit
FS          Field Separator
FS          File Separator
FSB         Front Side Bus
FSF         Free Software Foundation
FSK         Frequency Shift Keying
FT          Fault Tolerant
FTAM        File Transfer and Access Method
FTP         File Transfer Protocol
FTP         Foil Twisted Pair
FTTC        Fibre To The Curb
FTTH        Fibre To The Home
FTTP        Fibre To The Building
FUP         Funktionsplan

G
GAL         Global Address List
GATF        Graphic Arts Technical Foundation
GB          GigaByte (1,073,741,824 bytes)
GCR         Group Coded Recording
GDG         Generation Data Group
GDS         Global Directory Service
GDT         Global Descriptor Table
GDTR        Global Descriptor Table Register
GE          Graphic Escape
GETVIS      GET VIrtual Storage
GID         Group ID
GIF         Graphics Interchange Format
GIS         Generalized Information System
GIX         Global Internet Exchange
GKS         Graphical Kernel System
GML         Generalized Markup Language
GOSIP       Government OSI Profile
GP          General Protection
GPIB        General-Purpose Interface Bus
GRS         Global Resource Serialization
GS          Group Separator
GTF         Generalized Trace Facility
GUI         Graphical User Interface
GUIP        Graphical User Interface for Blind people
GUUG        German Unix User Group
H
H&J         Hyphenation and Justification
HA          Home Address
HA          Host Agent
HADA        High Availability Disk Array
HCL         Hue, Chroma, and Luminance
HDA         Head-Disk Assembl
HDBV        Host Data Base View
HDLC        High Level Data Link Communications
HDSL        High-bit rate Digital Subscriber Loop
HDTV        High Definition TV
HE          High End (system)
HGC         Hercules Graphics Card
HIC         Host Interface Computer
HLL         High Level Language
HLS         Hue-Lightness-Saturation
HMD         Head-Mounted Display
HMMP        HyperMedia Management Protocol
HMMS        HyperMedia Management Schema
HPCL        Hewlett-Packard Control Language
HPFS        High Performance File System
HPGL        Hewlett-Packard Graphical Language
HPR         High Performance Routing
HR          Horizontal Rule
HSB         Hue-saturation-brightness
HSELAN      High Speed ELAN
HSI         Hue-Saturation-Intensity
HSLAN       High Speed LAN
HSSI        High Speed Serial Interface
HSV         Hue-Saturation-Value
HT          Horizontal Tab
HTML        Hypertext Markup Language
HTTP        Hypertext Transfer Protocol
Hz          Hertz

I
I-Net       Intranet
I/O         Input/Output
I/O         Input/Output
IA5         International Alphabet Five
IAB         Internet Activities Board
IC          Integrated Circuit
ICEM        Integrated Computer Engineering and Manufacturing
ICMP        Internet Control Message Protocol
ID          Identifier
IDA         Indirect Data Addressing
IDA         Intelligent Drive Array
IDE         Integrated Drive Electronics
IDEA        International Data Encryption Algorithm
IDL         Interfacce Definition Language
IDT         Interrupt Descriptor Table
IEC         InterExchange Carrier
IEEE        Institute of Electrical and Electronic Engineers
IETF        Internet Engineering Task Force
IF          Interrupt Flag
IFF         Interchange File Format
IFIP        International Federation of Information Processing
IFS         Interchange File Separator
IFS         InterFrame Space
IGES        Initial Graphics Exchange Specification
IGMP        Internet Group Membership Protocol
IGS         Interchange Group Separator
II          Interactive Interface
IISP        Interim Interswitch Signaling Protocol
IKT         Informatione- und Kommunikationstechnik
ILC         InterLanguage Communication
IML         Initial Microcode Load
IMPL        Initial Microprogram Load
IMR         Interrupt Mask Registers
IMS         Information Management System
IMS/VS      Information Management System / Virtual Storage
INP         Inhibit Presentation
INT         INTerrupt
IOC         ISDN Ordering Code
IOCP        Input/Output Configuration Program
IOCS        Input/Output Control System
IOGEN       Input/Output device GENeration
IOPL        Input/Output Privilege Level
IOS         Input/Output Supervisor
IP          Internet Protocol
IPL         Initial Program Load
IPM         InterPersonal Message
IPSE        Integrated Project Support Environment
IPX         Internet Packet Exchange
IR          Index Return
IRC         Internet Relay Chat
IRDS        Information Resource Dictionary System
IRQ         Interrupt ReQuest
IRS         Interchange Recors Separator
IS          Information System
IS          Intermediate System
IS          International Standard
ISA         Industry Standard Architecture
ISAM        Indexed Sequential Access Method
ISDN        Integrated Services Digital Network
ISFMS       Indexed Sequential File Management System
ISMF        Interactive Storage Management Facility
ISO         International Standardization Organisation
ISO IEC     ISO International Electrotechnical Commitee
ISODE       ISO Development Environment
ISP         Internet Service Provider
ISPF        Interactive System Produvtivity Facility
ISPF/PDF    ISPF Program Development Facility
ISR         Information Storage and Retrieval
ISR         Intermediate Session Routing
ISSE        Intel SIMD Sreaming Extension
ISV         Independent Software Vendor
IT          Indent Tab
ITB         Intermediate Transmission Block
ITLD        International Top-Level Domain
ITRC        Information Technology Requirements Council
ITU         International Comunication Union (ehem. CCITT)
ITV         Interactive TeleVision
IUS         Interchange Unit Separator
IWS         Intelligent WorkStation

J
JCC         Job Control Command
JCL         Job Control Language
JCS         Job Control Statement
JCT         JES Control Table
JCT         Journal Control Table
JECL        Job Entry Control Language
JEIDA       Japan Electronics Industry Development Association
JES         Job Entry Subsystem
JPEG        Joint Photographic Experts Group

K
Kb           Kilobit
KB          KiloByte (1,024 Bytes)
KBPS        KiloBits Per Second
kHz         KiloHertz
KIP         Kinetics Internet Protocol
KIPS        Kilo Instructions per second
KL          Key Length
KOPS        Kilo Operations per second
KSDS        Key Sequenced Data Set
KVA         KiloVolt Ampere

L
L2F         Layer 2 Forwarding
L2TP        Layer 2 Tunneling Protocol
LAN         Local Area Network 
LAPS        LAN Adapter Protocol Support Program
LBL         Label
LCD         Liquid Crystal Display
LCS         Lotus Communication Server
LDAP        Lightweight Directory Access Protocol
LDMF        Librarian Disc Master File
LDS         Linear Data Set
LDT         Local Descriptor Table
LE          Low End (system)
LEC         LAN Emulation Client
LEC         Local Exchange Carrier
LED         Light Emitting Diode
LF          Linefeed
LIC         Line Interface Computer
LIFO        Last In, First Out
LILO        Last In, Last Out
LILO        Linux Loader
LIM-EMS     Lotus Intel Microsoft EMS
LIOCS       Logical Input/Output Control System
LISP        List Programming
LLC2        Logical Link Control Layer 2
LOC         Lines Of Code
LOS         Local Operator System
LPI         Lines Per Inch
LRC         Longitudinal Redundancy Checking
LRU         Least Recently Used
LSD         Least Significant Digit
LSI         Large Scale Integration -> VLSI
LU          Logical Unit
LUB         Logical Unit Block
LUT         Look Up Table
LVT         Light Valve Technology
LW          Line Work
LZ          Lempel-Ziv
LZW         Lempel-Ziv-Welch

M
MAC         Media Access Control
MAN         Metropolitan Area Network
MAP         Maintenance Analysis Procedure
MAP         Manufacturing Automation Protocol
MAPI        Messaging Applications Programming Interface
MB          MegaByte (1,048,576 bytes)
MBCS        Multiple Byte Character Set
MBONE       Multicast Backbone
MBPS        MegaBits Per Second
MCA         Micro Channel Architecture
MCBF        Mean Cycles Between Failures
MCCOI       Multimedia Communications Community of Interest
MCGA        MultiColour Graphics Array
MCI         Media Control Interface
MD          Management Domain
MD5         Message Digest 5
MDA         Monochrome Display Adapter
MEB         Memory Expansion Board
MFA         Modify Field Attribute
MFC         Microsoft Foundation Classes
MFKS        Multifunktionales Konferenzsystem
MFLOPS      Million Floating-Point Operations Per Second
MFM         Modified Frequency Modulation
MFV         Multi File Volume
MFWS        MultiFunction WorkStation
MGA         Monochrome Graphic Adapter
MH          Mobile Host
MHS         Message Handling System
MI          Multiple Inheritance
MIB         Management Information Database
MICR        Magnetic Ink Character Reader
MIDI        Musical Instrument Digital Interface
MIME        Multipurpose Internet Mail Extensions
MIPS        Millions of Instructions Per Second
MISC        Minimum Instruction Set Computer -> CISC, RISC
MLPPP       MultiLink PPP
MMDF        Multi-Channel Memorandum Distribution Facility
MMDS        Multi-Megabit Data Services
MMFS        Manufacturing Manage Format Standard
MMX         Multi Media eXtensions
MNP         Microcom Network Protocol
MODEM       MOdulator/DEModulator
MOPS        Mega Operations per second
MOTIS       Message-Oriented Text Interchange Systems
MP          Multiprocessing
MPC         Multimedia PC
MPEG        Motion Picture Experts Group
MPOA        MultiProtocol Over Asynchronous transfer mode
MPSD        MultiPath Storage Director
MPX         multiplex
MS          Message Store
MS-DOS      Microsoft Disk Operating System
MSA         Metropolitan Statistical Area
MSD         Most Significant Digit
MSG         Message
MSM         MultiSession Monitor
MSW         Machine Status Word
MTA         Message Transfer Agent
MTBF        MeanTime Between Failures
MTDA        Mean Time Data Availability
MTS         Message Transfer System
MUD         Multi-User Dungeon
MULTICS     MULTiplexed Information and Computing Service
MUMPS       Massachusetts General Hospital Utility Multi-Programmings                 System
MUMPS       Multi-User Multi-ProgrammingSystem
MVS         Multiple Virtual System
MVS/ESA     Multiple Virtual System / Extended System Architecture
MVS/XA      Multiple Virtual System / Extended Architecture
MVSCP       MVS Configuration Program

N
NAC         Network Adapter Card
NAK         Negative Acknowledgement
NAP         Network Access Point
NAS         Network Access Server
NAT         Network Address Translation
NAU         Network Addressable Unit
NBS         National Bureau of Standards
NBS         Numeric BackSpace
NC          Numeric Control
NCCF        Network Communication Control Facility
NCP         Network Control Processor
NCP         Network Control Program
NCP/VS      Network Control Program/Virtual Storage
NDIS        Network Driver Interface Specification
NetSP       Network Security Program
NFNT        New font numbering table
NFS         Network File System
NHRP        Next Hop Routing Protocol
NIC         Network Interface Card
NIC         Network Information Center
NIS         Network Information Service
NIST        National Institute for Standards and Technology
NJE         Network Job Entry
NL          New Line
NLQ         Near Letter Quality
NLT         Nucleus Load Table
NMI         NonMaskable Interrupt
NNTP        Network News Transport Protocol
NSA         National Security Agency
NSC1        Network Systems Cypher One
NSP         Numeric Space
NSS         NATURAL Security-System
NT          Network Termination
NTS/2       Network Transport Services/2
NTSC        National Television System Committee
NUI         Network User Identification
NUL         Null
NUMA        Non-Uniform Memory Access
NVOD        Near Video On Demand
NVRAM       NonVolatile Random Access Memory
NVS         NonVolatile Storage

O
O/R         Originator / Recipient
OC3         155 Mbit/s
OCR         Optical Character Recognition
OCX         OLE Control Extension
ODA         Open Document Architecture
ODSI        Open Directory Service Interfaces
OEM         Original Equipment Manufacturer
OI          Object Interface
OLE         Object Linking and Embedding
OLTEP       On-Line Test Executive Program
OLTP        On-Line Transaction Processing
OMG         Object Management Group
OMR         Optical Mark Recognition
OO          Objektorientierung
OOA         Objektorientierte Analyse
OODBMS      Object Oriented DBMS
OOP         Objektorientierte Programmierung
OOPL        Object Oriented Programming Language
OOPS        Object Oriented Programming System
OP          Operator Panel
OPI         Open Prepress Interface
ORB         Object Request Broker
OS          Operating System
OS/2        Operating System/2
OSA         Office Systems Architecture
OSA         Open System Architecture
OSF         Open Software Foundation
OSI         Open Systems Interconnection
OSI/RM      OSI Reference Model
OSNS        Open Systems Network Support
OSPF        Open Shortest Path First
OSTC        Open System Testing Consortium
OTPROM      One Time Programable ROM
OWL         Object Windows Library

P
PABX        Private Automatic Branch Exchange
PAD         Packet Assembly Disassembly
PAL         Phase Alternating Line
PAL         Programmable Array Logic
PAM         Partitioned Access Method
PAP         Password Authentication Protocol
PB          PetaByte (1,125,899,906,842,624 bytes)
PBX         Private Branch Exchange
PC          Personal Computer
PC          Personal Computing
PC          Program Control
PCB         Printed Circuit Board
PCB         Program Control Block
PCI         Peripheral Component Interface
PCI         Program Controlled Interuption
PCIL        Private Core Image Library
PCL         Printer Control Language
PCM         Plug Compatible Manufacturers
PCMCIA      Personal Computer Memory Card International Association
PCN         Personal Communication Network
PCP         Program Control Program
PCS         Personal Communication Services
PCT         Private Communication Technology
PCT         Program Control Table
PD          Public Domain
PDA         Personal Digital Assistant
PDAD        Proposed Draft Addendum
PDAU        Physical Data Access Unit
PDF         Program Development Facility
PDL         Page Description Language
PDO         Portable Distributed Objects
PDS         Partitioned Data Set
PDS         Premise Distribution System
PDS         Processor Direct Slot
PDU         Protocol Data Unit
PDX         Printer Description Extension
PE          Printer's error
PE          Protection Enabled
PEARL       Processor and Experiment Automation Realtime Language
PEM         Privacy Enhanced Mail
PEP         Partitioned Emulation Program
PER         Program Event Recording
PERL        Practical Extraction and Report language
PF          Parity Flag
PFK         Program Function Key(board)
PFM         Printer Font Metric
PGA         Professional graphics adapter
PGP         Pretty Good Privacy
PIB         Program Information Block
PID         Process ID
PIFS        Point InterFrame Space
PIM         Personal Information Management
PIN         Personal Identification Number
PIOCS       Physical Input/Output Control System
PL          Procedure Library
PL/1        Programming Language 1
PLI         Programming Language 1
PLPA        Pageable Link Pack Area
PLT         Program List Table
PLU         Primary Logical Unit
PMMU        Paged memory management unit
PMS         Pantone Matching System
PMS         Project Management System
PMT         Photomechanical Transfer (photostat)
PMT         Photomultiplier Tube
PNNI        Private Network-to-Network Interface
POC         Program-Operator Communication
POP         Point Of Presence
POP         Post Office Protocol
POSIX       Portable Operating System Interface for UNIX
POTS        Plain Old Telephone System
POWER       Priority Output Writer, Execution processors and input Readers
PP          Presentation Position
PPD         PostScript Printer Description
PPGA        Plastic Pin Grid Array
PPM         Pages Per Minute
PPP         Point-to-Point Protocol
PPT         Processing Program Table
PPTP        Point-to-Point Tunneling Protocol
PPV         Pay Per View
PRDMD       Private Directory Management Domain
PRL         Private Relocatable Library
PRMD        Private Management Domain
PROM        Programable Read Only Memory
PSB         Program Specification Block
PSDN        Packet Swiched Data Network
PSRAM       Pseudo SRAM
PSSL        Private Source Statement Library
PSTN        Public Swiched Telephone Network
PSW         Program Status Word
PTF         Program Temporary Fix
PTR         PoinTeR
PU          Physical Unit
PUB         Physical Unit Block
PVC         Permanent Virtual Circuit
PVP         Packet Video Processor
PWB         Printed Wire Board
PWS         Programmable WorkStation

Q
QAM         Quadrature Amplitude Modulation
QBE         Query By Example
QCIF        Quater Common Intermediate Format
QIC         Quarter-Inch Cartridge
QSAM        Queued Sequential Access Method
QTAM        Queued Teleprocessing Access Method

R
R0          Record zero
RACF        Resource Access Control Facility
RAID        Redundant Array of Inexpensive Disks
RAID        Redundant Array of Independent Disks
RAM         Random Access Memory 
RARP        Reverse Address Resolution Protocol
RBA         Relative Byte Adresse
RC          Robot Control
RCP         Remote Communication Processor
RCS         Revision Control System
RDA         Remote Data Access
RDBMS       Relational DataBase Management System
RDN         Relative Distinguished Name
RES         Restore
RF          Resume Flag
RFC         Request For Comments
RFF         Required Form Feed
RFS         Remote File System
RGB         Red, Green, Blue
RGM         Red, Green, Blue (Monitor)
RIFF        Resource Interchange File Format
RIP         Raster Image Processor
RIP         Router Information Protocol
RISC        Reduced Instruction Set Computer
RJE         Remote Job Entry
RL          Relocatable Library
RLD         Relocation Dictionary
RLE         Run Length Encoded file
RLL         Run Length Limited
RMF         Resource Management Facility
RNL         Required New Line
ROM         Read Only Memory 
RPC         Remote Procedure Call
RPG         Report Program Generator
RPL         Requestor's Privilege Level 
RPL         Research Programming Language
RPM         Revolutions Per Minute
RPS         Rotational Position Sensing
RPT         Repeat
RRDS        Relative Record Data Set
RRED        Right Reading Emulsion Down
RREU        Right Reading Emulsion Up
RS          Record Separator
RSP         Required Space
RSVP        Resource Reservation Protocol
RTC         Real Time Clock
RTCP        Realtime Transport Control Protocol
RTF         Rich Text Format
RTM/SF      Realtime Monitor / Systems Facility
RTP         Realtime Transport Protocol
RTSE        Reliable Transfer Service Element
RWSI        Remote Workstation Interface

S
S.W.I.F.T.  Society for Worldwide Interbank Financial Telecommunication
S/STP       Shielded STP
SA          Set Attribute
SAA         Storage Accounting Area
SAA         System Application Architecture
SAM         Sequential Access Method
SAP         Service Access Point
SAP         Service Advertising Protocol
SAR         Segmentation And Reassembly
SBCS        Single Byte Character Set
SBS         Subscript
SC          Storage Control
SCA         Shared Control Array
SCCS        Source Code Control System
SCDS        Source Control Data Set
SCI         Scalable Coherent Interconnect
SCODL       Scanned Conversion Object Description Language
SCP         Storage Control Program
SCP         System Control Program
SCRAM       Static Column Random Access Memory
SCSI        Small Computer Systems Interface
SDH         Synchronous Digital Hierarchy
SDK         Software Development Kit
SDL         System Directory List
SDLC        Synchronous Data Link Control
SDRAM       Synchronous DRAM
SDSF        System Display and Search Facility
SE          Software Entwicklung
SE          System Engineer
SECC        Single Edge Contact Connector
SECAM       Sequential Couleur a'Memorie
SEL         Select
SEPP        Single Edge Processor Package
SET         Software-Engineering-Technology
SF          Sign Flag
SF          Support Facility
SFA         Salesforce Automation
SFBI        Shared Frame Buffer Interconnect
SFE         Start Field Extended
SFT         System Fault Tolerance
SFTP        Shielded Foil Twisted Pair
SGML        Standard Generalized Markup Language
SHTTP       Secure HTTP
SHY         Syllable Hyphen
SI          Shift In
SI          Single Inheritance
SI          Standard Interface
SIFS        Short InterFrame Space
SIFT        Stanford Information Filtering Tool
SIG         Special Interest Group
SIM         Service Information Message
SIMD        Single Instruction Multiple Data
SIMM        Single In-line Memory Module
SIRDS       Single Image Random Dot Stereogram
SIT         System Initialization Table
SL          Source Statement Library
SLD         Structured Logic Design
SLED        Single Large Expensive Disk
SLIP        Serial Line Internet Protocol
SLR         Service Level Reporter
SLU         Secondary Logical Unit
SM          Set Mode
SMDS        Switched Multimegabit Data Service
SMF         System Management Facility
SML         MVS Storage Management Library
SMLI        Stateful MultiLayer Inspection
SMP         Symetric MultiProcessing
SMP         System Modification Program
SMS         Storage Management Subsystem
SMTP        Simple Mail Transfer Protocol
SNA         System Network Architecture
SNADS       SNA Distribution Services
SNMP        Simple Network Management Protocol
SNOBOL      String Oriented Symbolic Language
SNT         Sign-On Table
SO          Shift Out
SOD         Service On Demand
SOH         Start Of Heading
SOM         System Object Model
SOS         Start Of Significance
SP          Space
SPA         Software Publishers Association
SPARC       Scalar Processor ARChitecture
SPDU        Session Protocol Data Unit
SPM         System Performance Monitor/2
SPOOL       Simultaneous Peripheral Operations On Line
SPP         Scalable Parallel Processing
SPS         Superscript
SPX         Sequenced Packet eXchange
SQL         Structured Query Language
SQL/DS      Structured Query Language / Data System
SRAM        Static Random Access Memory
SRT         System Recovery Table
SRU         Shared Resource Unit
SS          Single Sided
SS          Stack Segment
SSCP        System Service Control Point
SSID        SubSystem IDentifier
SSL         Secure Socket Layer
STM         Synchronous Transfer Mode
STP         Shielded Twisted Pair
STT         Secure Transaction Technology
STX         Start of Text
SUB         Substitute
SV          Storage Violation
SVA         Shared Virtual Area
SVC         Supervisor Call
SVC         Switched Virtual Circuit
SVGA        Super-VGA
SW          Switch
SWOP        Specifications for Web Offset Printing
SYN         Synchronous Idle
SYSOP       System Operator

T
T1          1.544 Mbit/s
T3          45 Mbit/s
TARGA       Truevision Advanced Raster Graphics Adapter
TB          TeraByte (1,099,511,627,776 bytes)
TC          Terminal Control
TCA         Task Control Area
TCAM        Telecommunications Access Method
TCB         Task Control Block
TCL         Tool Command Language
TCM         Thermal Conduction Module
TCO         Triple Capacity Option
TCP         Terminal Control Program
TCP         Transmission Control Protocol
TCP/IP      Transmission Control Protocol/Internet Protocol
TCT         Terminal Control Table
TCTTE       Terminal Control Table Terminal Entry
TCU         Transmission Control Unit
TD          Transient Data
TDIA        Transient Data Input Area
TDM         Time-Division Multiplexing
TDOA        Transient Data Output Area
TDP         Transient Data Program
TEO         Technical Electronic Office
TF          Trap Flag
TIC         Technical Integrity Check
TIFF        Tagged Image File Format
TIOA        Terminal Input/Output Area
TLB         Translation Lookaside Buffer
TLBL        Tape Label
TMO         Thermo-Magneto-Optic technology
TNEF        Transport-Neutral Encapsulation Format
TOC         Table Of Contents
TOP         Technical Office Protocol
TPDU        Transport Protocol Data Unit
TPF         Transaction Processing Facility
TPI         Tracks Per Inch
TPM         Third-Party Maintenance
TPS         Transactions Per Second
TRN         Transparent
TS          Telecommunication System
TS          Temporary Storage
TSIOA       Temporary Storage Input/Output Area
TSO         Time Sharing Option
TSP         Temporary Storage Program
TSR         Terminate and Stay Resident
TTA         Teletex Attachment (Teletexzusatz)
TTL         Transistor Transistor Logic
TTR         Track Record
TTY         TeleTYpe
TWA         Transaction Work Area
TWA         Two-Way Alternate
TWS         Two-Way Simultaneous
TX          Telex
TXT         Text

U
UA          User Agent
UAE         Unrecoverable Application error
UART        Universal Asynchronous Receiver/Transmitter
UBR         Undefined Bit Rate
UBS         Unit Backspace
UCB         Unit Control Block
UCR         Undercolor removal
UCS         Universal Character Set
UCSB        Universal Character Set Buffer
UCW         Unit Control Word
UDP         User Datagram Protocol
UI          User Interface
UID         User ID
UMB         Upper Memory Block
UNC         Universal Naming Convention
UNC         Universal Network Convention
UPC         Universal Product Code
UPS         Uninterruptible Power Supply
UPSI        User Program Switch Indicator
UR          Unit Record
URL         Uniform Resource Locator
US          Unit Separator
USART       Universal Synchronous/Asynchronous Receiver/Transmitter
USENET      USEr NETwork
USM         UnSharp Masking
USRT        Universal Synchronous Receiver/Transmitter
USV         Unterbrechungsfreie StromVersorgung
UTP         Unshielded Twisted Pair
UUCP        Unix-to-Unix Copy Program

V
VAD         Value Added Dealer
VAN         Value Added Network
VAP         Value Added Process
VAR         Value Added Reseller
VAST        Virtual Archive Storage Technology
VB          Visual Basic
VBA         Visual Basic for Applications
VBR         Variable Bit Rate
VBN         Vermitteltes Breitbandnetz
VC          Virtual Circuit
VC-SDRAM    Virtual Channel SDRAM
VCC         Virtual Circuit Connection
VCI         Virtual Circuit Identifier
VCNA        Vtam Communication Network Application
VCPI        Virtual Control Program Interface
VDAC        Video Digital Analog Converter
VDI         Video Display Interface
VDT         Video Display Terminal
VDU         Visual Display Unit
VERONICA    Very Easy Rodent-Oriented Netwide Index to Computerized Archives
VGA         Video Graphics Array
VGC         Video Graphics Controller
VGM         Video Graphics Monitor
VHDSL       Very High-bit rate Digital Subscriber Loop
VHLL        Very High-Level Language
VHS         Video Home System
VIO         Video Input/Output
VIO         Virtual Input/Output
VIPA        Virtual IP Addressing
VLAN        Virtual LAN
VLSI        Very Large Scale Integration
VM          Virtual Machine
VM/SP       Virtual Machine / System Product
VMMAP       VM Monitor Analysis Program
VMOS        Vertical MOS
VMPPF       VM Performance Planning Facility
VMPRF       VM Performance Reporting Facility
VMS         Virtual Management System
VOD         Video On Demand
VPD         Vital Product Data
VPDN        Virtual Private Data Network
VPI         Virtual Path Identifier
VPN         Virtual Private Network
VR          Virtual Reality
VRAM        Video RAM
VRML        Virtual Reality Modeling Language
VRC         Vertical Redundancy Checking
VS          Virtual Storage
VSAM        Virtual Storage Access Method
VSAT        Very Small Aperture Terminal
VSM         Virtual Storage Management
VSN         Volume Serial Number
VT          Vertical Tab
VTAM        Virtual Telecommunications Access Method
VTOC        Volume Table of Contents
VTP         Virtual Terminal Protocol
VTP         Virtual Terminal Program
VTX         VideoTeXt
VVDS        VSAM Volume Data Set

W
W3          World Wide Web
W4WG        Windows for Workgroups
WABI        Windows Application Binary Interface
WAIS        Wide Area Information Service
WAN         Wide Area Network
WATM        Wireless ATM
WATS        Wide Area Telecommunications Service
WHAT        Wireless Hybrid Asynchronous Time-bounded
WIMP        Windows, Icons, Mice and Pointers
WINS        Windows Internet Name Service
WMAC        Wireless Media Access Control
WMF         Windows metafile
WORM        Write Once, Read Many times
WOSA        Windows Open Services/Systems Architecture
WRED        Wrong Reading Emulsion Down
WREU        Wrong Reading Emulsion Up
WS          WorkStation
WTO         Write To Operator
WUS         Word Underscore
WWW         World Wide Web
WXTRN       Weak External Reference
WYSIWYG     What You See Is What You Get

X
XA          EXtended Architecture
XIP         Execute In Place
XLT         Transaction List Table
XMS         Extended Memory Specification
XT          eXtended Technology

Y
Y2K         Year 2000
YIQ         (color components in NTSC color space)
YUV         (color components in SECAM and PAL color spaces)

Z
ZBR         Zero Bug Release
ZD          Zero Defects
ZF          Zero Flag