The school board could simply state that the appropriate dress for the graduation ceremony is either the cap & gown or a military uniform if you have proof of current enlistment. Then you won’t have the problem of “other” groups trying to wear strange outfits just to stand out from the crowd.
nice idea but won’t work..too many groups would bring “doctors notes” saying, hey, anatomically they’re a guy, but really they’re a girl..(read: discrimination suits)
end result, wear the dress uniform under the cap and gown..
Trust me, if you make an exception for Service members, you will end up with exceptions for homosexuals and transvestites and Goths and Punks and all other forms of fashion depravity.
The uniform of the day is a cap and gown. There ought not to be any exceptions, otherwise why have a "uniform" at all. He earned the right to wear his dress blues, but only when it is appropriate. He also has earned the right to wear a cap and gown. He should wear that "uniform" with equal pride and not try to stand out from the crowd.