The clean shirt policy has to do more with state/association patches and the like. You CAN wear a flag, it IS optional, and the location is specified in the post I made above.

That said, I will never wear a flag patch on my football uniform. I can't imagine my crew pushing for it and I certainly won't.

Some people feel the need to literally wear their patriotism on their sleeve.

What is the rationale behind that?

What if I work in a league that has teams from Canada?

What if I am Canadian and living in Wisconsin? Can I wear the Canadian flag?

You might consider it simply paying respect to and honoring all those who are spread all around the globe, in harm's way, protecting your right and ability to enjoy participating in a great game without fear.

If you work with Canadian teams, you might consider adding a Canadian flag as a sign of respect for the Canadians who are working with the Americans listed above.

If you're a Canadian living in Wisconsin, you might think of wearing an American flag as a sign of respect and/or thanks to your host. Wearing a Canadian flag might be more relevant to games you work in Canada.