Syntax for server parameters to client messages?

[jwodder]

Various client messages take one or more parameters that refer to servers (e.g., CONNECT, SQUIT, and TIME), but the documentation doesn't seem to describe the actual format of these parameters, aside from a note at the end of the "Servers" section that "Servers SHOULD pick a name which contains a dot character". Can one assume that server parameters follow the same grammar as DNS names, or can they be non-DNS strings like the "host" portion of sources (Cf. #168)?

[progval]

They can be non-DNS strings. If you're writing a client, just assume it can be any string that fits the wire format.