I read the previous posting.
You should check the deed for the lot in the unincorporated part of the county. It could be subject to deed restrictions. Your deed should tell you.
Here's a brief primer on deed restrictions. Deed restrictions are placed on real property by the original developer. They may "run with the land" which means they can last forever regardless of who owns the lot and how many times it changes ownership. Anyone who owns a lot in a subdvision covered by deed restrictions can enforce them against any other person who owns a lot in the subdivision. Should your lot be part of a subdivision of more than one lot and should it have a deed restriction against flagpoles, anyone who owns a lot in the subdivision could force you to remove your flagpole.
Now you have a bit more education.