One of my bug bears at weddings is the registrars and priests insistence on no photography during the signing of the register...
Yes - guests should stay seated and not take pictures of the official signing, but come on - let the 'official photographer' use his or her's professional discretion to get some candid shots.
The signing is the first time that the bride and groom can have a little chat after becoming man and wife and more often than not the bride and groom are relaxed and enjoying the fact that the ceremony is done and they know its drinks from here on in!
I get that the signing of the register is a legal requirement and the document has names, address and occupations of the bride, groom and the witnesses - but any professional photographer knows that and would frame any shots to make sure that the legal bits were not framed in shot.
Maybe one day it will change, but probably not!
Anyway - here a few of my favourite stealthy shots... just don't tell the wedding police!