Do validations only allow true or false

[joebordes]

the second is NOT a buisness action: it is an event handler, it is done in the code: https://github.com/tsolucio/corebos/blob/master/build/HelperScripts/coreBOSEventsLoader.php#L19

as to the first method, forget about it: create a custom validation script like you did for the inventory modules and do whatever you want