I find nothing wrong with a small sign like that to announce a meeting place and time.

The use of the X Marks Tartan, Cap Badge, or Forum Logo would be acceptable for such a sign.

The only thing I would have an issue with is a tent or booth set up with a banner saying something like "Clan X Marks".

Or someone in a tent or booth recruiting for, or claiming to represent the forum.



Could a group of members forum a tug of war team? Sure.
Could a group of members march in the Clan Parade holding up a banner proclaiming to be representative of X Marks? No.

I guess it is a small nit pick thing but if you look at it from the standpoint of others attending the event, will they see a group and think "Wow, that group of people are having a good time." Or will they see a group and think "Oh My, that X Marks, who do they think they are?"

Do you see the distinction?