Basic general information about the protocols: creator, version, etc. Note 1: In ~usr@a.b.com, the a.b.com part is known as the "hostmask" and can either be the server being connected from or a "cloak" granted by the server administrator; a more realistic example is ~myname@myisp.example.com. The tilde generally indicates that the username provided by the IRC client on signon was not verified with the ident service. Note 2: In usr@a.b.c/home, the ...

See also:

Comparison of instant messaging protocols, Comparison of instant messaging protocols - General information

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