Ichigo_Kurosaki was acting Substitute Shinigami in NOVA server until he went MIA.
The ultimate law is to maintain balance.
It is against the law for a Shinigami to give intel to Enemy Guilds.
It is against the law for a Shinigami to use forbidden knowledge outside the Gotei 13.
It is against the law for any citizen of Soul Society to create weapons of a dangerous nature not sanctioned by the feudal government. To do so is treason.
It is against the law to attack a captain. To do so is treason.
It is against the law to commit terrorist action(s) or attempt to overthrow the balance of Soul Society. To do so is treason.
It is against the law to commit murder to any Shinigami fleets.
It is against the law to kill a Human guild that a Shinigami has not been ordered to kill.
It is forbidden for a Shinigami to acquire or attempt to gain Hollow-like powers.
It is against the law for the Gotei 13 to meddle in the affairs of the noble families unless the family in question breaks one of the laws of Soul Society beyond a shadow of a doubt.
It is by ancient law that two Shinigami cannot hold the same Zanpakutō. They must fight for the honor of bearing the spirit, with the spirit going to the winner, and the loser being executed.
It is forbidden for a Shinigami to intervene in anything that is related to Hell.
All Modified Souls must be scrapped.