no rusty, i'm certain he should have been given ILE and the embassy have up.

give UKBA a call, it's an incorrect endorsement.
http://www.ukba.homeoffice.gov.uk/po...ecg/ecb/ecb19/


he cannot apply for citizenship because he's under 18, but he can register as British using form MN1 the same time your wife applies for citizenship.

http://www.ukba.homeoffice.gov.uk/br...ritishcitizen/

Section 3(1) application - children who do not come under section 1(3) or section 1(4) whose parents are applying for British citizenship

If one or both of the child's parents are applying for British citizenship we may, if we believe it is reasonable under the circumstances, register the child under section 3(1) of the British Nationality Act 1981. We will normally only register the child if:

both parents are granted or already hold British citizenship; or
if one parent holds British citizenship and the other is settled in the United Kingdom.


http://www.ukba.homeoffice.gov.uk/br...izen/borninuk/