There seems to be a debate on that with different organizations taking different positions. At our school, it's standard procedure. The Treasurer keeps the books and controls the account, but the President and the Principal both have authorization to sign the checks.
Our policy is that every check have two signatures. The Principal FREQUENTLY acts as the second signature for us. I think that once (maybe the treasurer was out of town??) that the Principal initiated a check - but it was for a routine payment that had already been approved.
