Why do not you go to your municipality or VDC and get a letter, they will write a letter that you were born to Mr.... and Mrs..... and on ............ AD (BS) and place of birth. Have them write in English for easiness.

That will suffice. In addition to submitting school leaving certificate's DOB, I submitted a letter from my VDC stating my place of birth, date of birth and my parents' name (both mother and father), USCIS did not even ask anything, no RFE issued for me.

You can take your own wording and have the municipality or VDC write a letter for you. The letter was written like this by VDC on its letter pad as follows:

To whom it may concern:

The BOD register maintained at this VDC indicates that Mr...... was born to Mr ...... and Mrs ......... on ........... (AD) BS at .........

Hope this helps.