Hi Louis
As Graham said, just go along with their little rules. .luck or as it now seems unlucky for me, my wife wasn't asked for such proof.
The next hoop of fire you got to jump through is luggage. ..namely keeping within luggage allowance. .most other countries allow a small margin of being over weight, this does not apply in the Philippines. ..believe you me, the Philippine airport authorities have turn't it into a nice little earner.
If they can extract even more of your hard earned, they will. Make sure you weigh your bags before leaving for the the airport.