Re: limitations of a nick?

["Grega" <grega@xxxxxxxxxx>]

> is the length of a nick specified?

It is limited with:
#define    NICKLEN         9
in common/struct_def.h

All servers on a network MUST have the same length of nicks, else
you get problems (the servers with shorter NICKLEN will kill
the users with longer nicks).
With 2.11 ircd there are preparations to extend that limit to 12 in
future versions (obviously the limit can't be just raised when there
are still older servers linked).

> what are the limitations to the character set?

**  Nickname characters are in range
**      'A'..'}', '_', '-', '0'..'9'
**  anything outside the above set will terminate nickname.
**  In addition, the first character cannot be '-'
**  or a Digit.

(from ircd/s_user.c)

"anonymous" is disallowed because of +a channel mode
And there are some tricks due to the scandinavian origin of IRC
(for example | and \ is the same character - one being upper and one
lower case). That is about to get dropped with 2.11.

Greetings,
fiction