"Letter of Freedom"

My brother is getting married in October.
He is getting married in a catholic church, though he isn't catholic.
I never thought about it (and honestly never had any reason to) but there are some complicated elements to having a non-catholic get married in a catholic church - or at least the one my brother is getting married in.

Certificate of baptism - I've recently gotten the impression that my dad is forging one because my brother doesn't have his official one from when he was baptised as a kid. Kind of ironic - to forge a document in order to prove you're "in" with God.

At the altar - it's my understanding that there are rules about where you are allowed to stand in relation to the altar during a wedding in a catholic church, depending on whether you are catholic or not.

My personal favorite has got to be the "Letter of Freedom" that my parents have to sign to assure the church that my brother is not already married to someone else and that there is no reason why he shouldn't be allowed to marry his fiancée. I guess it clears up potential "if anyone has reason to believe they should not be joined, speak now..." drama by getting it done ahead of time.