Recommended SSID Assignments
An SSID (Secondary Station Identifier) is a number following
a station's callsign. The numbers range from -0 to -15 and are used to
identify the type of packet service the station is running.
-0 Home station (note: "-0" not needed - automatically presumed if no SSID.)
-1 Home station personal mailbox (usually a TNC-based PBBS).
-3 Full service BBS's (those that forward mail and bulletins).
-4 Network Nodes (having two or more radio ports that perform routing functions via TCP/IP, NetROM, etc.) (Can be combined with BBS's that also perform routing.)
-5 Console, keyboard or printer
-6 Conference Bridges
-7 Crossband digipeaters (and KA-Nodes)
-8 Crossband digipeaters
-10 Winlink 2K
-15 Often used as a downlink address when exiting the far end of a network connection.
The above assignments are from http://www.mi-drg.org/ssid.shtml and are only listed here as an example. Local usage may vary widely from the above.