secret diplomacy and general cheating guidelines

A general question:
someone approached me today in a PM about a strategy in a game you're both in, does that count as secret diplomacy (I would think so)? And: what is the punishment if I were to report it and he gets busted? Sorry if this has already been posted, but I cannot seem to find it if so...
I just don't want to report anyone before I know what the consequences will be for them... Also, the player has quite a good ranking and rating, that made me think that this is more common than I thought eventhough it is prohibited??
Thanks
someone approached me today in a PM about a strategy in a game you're both in, does that count as secret diplomacy (I would think so)? And: what is the punishment if I were to report it and he gets busted? Sorry if this has already been posted, but I cannot seem to find it if so...
I just don't want to report anyone before I know what the consequences will be for them... Also, the player has quite a good ranking and rating, that made me think that this is more common than I thought eventhough it is prohibited??
Thanks