It is considered multiplay to use knowledge from one of your characters
in another. This is something that is hard to do alot of the time and some
of it does naturally leak over from one character to the other.
In the situation where we decided it was a strikable offence it was because
it went against the precepts of fair play. Someone had died and when they
reincarnated to Market Square and told others of what had had happened to
them several players immediately logged off their good characters to log
in evil ones to participate in the roleplay of the aftermath of the death
of that character, and gain such benefits as equipment from the looting of
the corpse.
This was poor form, and it hurt the player of the character who died when
those who might have been in character to help him left him, and used the
information in other characters to their benefit.