| 1||Hardware platform|
Code to identify the type of hardware installed in a computer environment e.g. PC, Mac, UNIX-Workstation, Mini, Mainframe.
| 2||Operating system|
Code to identify the operating system, like DOS, VMS, etc. used in a computer environment.
| 3||Application software|
Code to identify an application software, like AutoCad, WinWord, etc. used in a computer environment.
Code to identify a network like Ethernet, Token Ring, etc. implemented in a computer environment.
| 5||Sending system|
Code to identify the system, which acts as a sending system in an interchange.
| 6||File generating software|
Software used to generate a file.
| 7||File compression software|
Software used for the compression of a file.
| 8||File compression method|
Method used for the compression of a file.