| Kind | Value | Annotation |
| enumeration | AA | | documentation | | Circuit switching - A process that, on demand, connects two or more data terminal equipments and permits the exclusive use of a data circuit between them until the connection is released (ISO). |
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| enumeration | AB | | documentation | | SITA - Communications number assigned by Societe Internationale de Telecommunications Aeronautiques (SITA). |
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| enumeration | AC | | documentation | | ARINC - Communications number assigned by Aeronautical Radio Inc. |
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| enumeration | AD | | documentation | | AT&T mailbox - AT&T mailbox identifier. |
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| enumeration | AE | | documentation | | Peripheral device - Peripheral device identification. |
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| enumeration | AF | | documentation | | U.S. Defense Switched Network - The switched telecommunications network of the United States Department of Defense. |
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| enumeration | AG | | documentation | | U.S. federal telecommunications system - The switched telecommunications network of the United States government. |
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| enumeration | AH | | documentation | | World Wide Web - Data exchange via the World Wide Web. |
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| enumeration | AI | | documentation | | International calling country code - Identifies that portion of an international telephone number representing the country code to be used when calling internationally. |
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| enumeration | AJ | | documentation | | Alternate telephone - Identifies the alternate telephone number. |
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| enumeration | AK | | documentation | | Videotex number - Code that identifies the communications number for the online videotex service. |
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| enumeration | AL | | documentation | | Cellular phone - Identifies the cellular phone number. |
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| enumeration | AM | | documentation | | International telephone - Telephone number, including country and/or city code as required, for voice or data transmission by telephone beyond the border of a country. |
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| enumeration | AN | | documentation | | O.F.T.P. (ODETTE File Transfer Protocol) - ODETTE File Transfer Protocol. |
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| enumeration | CA | | documentation | | Cable address - Self explanatory. |
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| enumeration | EI | | documentation | | EDI transmission - Number identifying the service and service user. |
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| enumeration | EM | | documentation | | Electronic mail - Exchange of mail by electronic means. |
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| enumeration | EX | | documentation | | Extension - Telephone extension. |
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| enumeration | FT | | documentation | | File transfer access method - According to ISO. |
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| enumeration | FX | | documentation | | Telefax - Device used for transmitting and reproducing fixed graphic material (as printing) by means of signals over telephone lines or other electronic transmission media. |
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| enumeration | GM | | documentation | | GEIS (General Electric Information Service) mailbox - Self explanatory. |
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| enumeration | IE | | documentation | | IBM information exchange - Self explanatory. |
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| enumeration | IM | | documentation | | Internal mail - Internal mail address/number. |
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| enumeration | MA | | documentation | | Mail - Postal service document delivery. |
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| enumeration | PB | | documentation | | Postbox number - Self explanatory. |
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| enumeration | PS | | documentation | | Packet switching - The process of routing and transferring data by means of addressed packets so that a channel is occupied only during the transmission. |
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| enumeration | SW | | documentation | | S.W.I.F.T. - Communications address assigned by Society for Worldwide Interbank Financial Telecommunications s.c. |
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| enumeration | TE | | documentation | | Telephone - Voice/data transmission by telephone. |
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| enumeration | TG | | documentation | | Telegraph - Text transmission via telegraph. |
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| enumeration | TL | | documentation | | Telex - Transmission of text/data via telex. |
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| enumeration | TM | | documentation | | Telemail - Transmission of text/data via telemail. |
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| enumeration | TT | | documentation | | Teletext - Transmission of text/data via teletext. |
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| enumeration | TX | | documentation | | TWX - Communication service involving Teletypewriter machines connected by wire or electronic transmission media. Teletypewriter machines are the devices used to send and receive signals and produce hardcopy from them. |
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| enumeration | XF | | documentation | | X.400 - CCITT Message handling system. |
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