frankdrebs -- ito lang ang sagot ko but paki validate na rin sa ibang abogado kasi wala akong hawak na text book dito and there might have been some new decisions by our supreme court on these provisions also. stock knowledge lang ito so here goes:

1. (5) Those contracted through mistake of one contracting party as to the identity of the other; and <-- pakiexplain naman ito sa mga dumb persons like me -- pare, hindi ka naman dumb. the only dumb questions are those that are not asked, hehehehe. an example i can give you is in the case of twins and i mean look alike twins. for some reason you did not marry the right one but the other twin. of course the chances of this happening is unlikely but still, malay mo, hahahaha.

2. Art. 53. Either of the former spouses may marry again after compliance with the requirements of the immediately preceding Article; otherwise, the subsequent marriage shall be null and void. <-- also this one. -- this means that if the marriage was void, they can contract the marriage again but they have to follow all the requirements na. for example, nag asawa when they were 15. this is void ab initio. they both are already 25, this does not make their marriage valid. to cement the bond, they should marry again but this time get all the necessary permits and licenses. kung aba sa natirik na sasakyan (kasi nasa tsikot.com tayo) i jump start, hehehehe

i hope that i was helpful