Back ON-topic....

I understand and realize that there are many libertarians on this forum -- people who take their personal freedoms and the rights of others very seriously. That is naturally a good thing. There's a reason why there are laws in the U.S. that protect religious and cultural expression, and other laws that make it necessary to accommodate those with special needs (like the Americans with Disabilities Act). Nothing wrong with that.

However, human nature will always prevail and let me state it bluntly: just because a law book says you have the RIGHT to do something doesn't mean everyone thinks you should. Whether or not you take it upon yourself to show such a person the error of their ways is really what's at stake here.

I don't think anyone here denies that we should have the RIGHT to wear a kilt to work (based on cultural diversity, freedom of expression, et cetera, and barring safety issues or other hazards), but to what extent is it wise to push for that right?

Remember, that the OP's manager used the word unprofessional to describe the kilt. What that tells me, is that everything else is moot. Invoking HR (or in this case, NOT invoking HR) is simply just the manager's attempt to legitimize his opinion that wearing a kilt is unprofessional. Perhaps he thinks it looks unmasculine. Maybe he just thinks men wearing kilts look strange. Maybe he feels that employees should all look a certain way. We don't know. What we DO know is that all the HR personnel in the world, with all the employee handbooks, and all the company policies, and all the individual protection laws, and all the ACLU activists in the world are most likely irrelevant unless they directly address why he dislikes kilts. They may well be able to FORCE the manager to comply and allow the OP to wear his kilt, but that doesn't mean that the manager will like it. Plus, if he is shown to be wrong, he will have lost face, which means he will like it even less.

So when it comes to working for a manager who: a) STILL thinks you are dressed inappropriately when b) he has been dressed down by top brass and c) has been made to lose face in front of everyone.... What are the chances that it will remain a pleasant place to work? Very little, I would say.

I know it may be distasteful to do so, but just put yourself in the manager's shoes. Think about it from his perspective. You've just arrived at work, and the first thing you see is one of your employees dressed unprofessionally. You've spoken to him about it but he asserts that he already cleared it with HR and they said it was okay. So you tell him that you'll put up with it just this day, but to please not come dressed like that in the future...

You think that's the end of it, but a few days later you get a call from an HR manager at head office who wants to talk to you about cultural diversity. You learn that someone in your store has been causing trouble for you at head office and going over your head. And now, they are telling you that you don't have the right to stop YOUR employees from expressing themselves, in spite of the fact that it would make them look like complete clowns, embarrassing you, and making the store look like a joke! Not to mention the fact that now, every time this guy looks like crap, all the other staff will look at YOU and think that YOU'RE the bad guy... How does that make you feel about that employee that started this whole mess? What's going to go through your head each time you have to look at him? Human nature says you're probably going to be pretty resentful and not like him very much after that...

Anyway, I'm not saying NOT to fight this. I'm not saying DON'T go to HR and get the official go-ahead to wear a kilt. But just realize that by doing so, you may end up alienating the manager, and making your overall work situation a lot less pleasant than before. Ergo, consider very carefully whether this is a fight really worth fighting. It IS possible in cases like this to win the battle but lose the war.