section 12 flr m

[jaymids200]

hi all, so far filling in the form has been a night mare, could someone please help me.
FLR-M
section 4 PAGE 15,16
dependent children bit ive filled it in but my eldest son(British/ Thai nationality) his passport is out of date so still fill in the details? but to write expired?
then in section 12, page 58, dependents, well as my sons have are British passport do i still need to fill this out and fill in their details, even though it asks for valid passport to which 1 is out of date, i am providing original birth certificates any way with this application.
only reason im confuses as in section 13 it goes on to say that supply passports named in section 4 and are applying for extension of stay in the uk with you, to which they arent applying as they are British.