Can they wear military dress hats indoors?
This depends on the branch of service you are questioning. The Army wears covers whilst under arms. The Marines wear covers whilst under arms, or for full honor guard funeral, unless in Catholic services, where cover is never permitted indoors. The Navy and Air Force remove cover whilst indoors, unless for a Jewish service or function. Then the religious dictates overrule the military ones. Covers are replaced when leaving the building it is performed in. When removed, cover is placed under the left arm. I have done seventy military funerals for veterans in full dress uniform and have never worn a cover indoors. But I am Catholic and have never been asked to do a Jewish service, so I defer to their rulings. But for the real poop, I’d consult the service’s regulations to get the answer. I have been playing bagpipe ‘Amazing Grace’ for military funerals for 45 years, and have yet to wear cover indoors for ANY church service except for a Jewish wedding.