Thanks for the quick reply.
Is there a way to base a legal argument over the fact that there is no relationship, we're not bound in any way or neither in contact, so for, there is no reason for him to include me in his application?
My distant half brother in law is applying for jobs with the government. The application requires for him to provide all his/spouse extended family information, but the application states only family members with whom you or your spouse are bound by affection, obligation, or close and continuing...