If we use the NSO verified marriage certificate we have now I may ask my wife to write in her supporting letter something along the lines of this:

"In accordance with the UK Border Agency list of supporting documents, included is a marriage certificate verified, signed and stamped by the Philippine National Statistics Office (NSO).

As we have recently married (September 21st 2012), this certificate is not on NSO paper, as it can take 6 months for such a certificate to be issued if it is sent automatically and not fast tracked from the local registry office to the NSO.

I recently renewed my passport and needed evidence to update my marital status on my passport. The NSO verified, signed and stamped this marriage certificate, a legal document, making it valid for a DFA Philippine passport renewal."