Trademark dispute

The fedora.info site of the complaining fedora project is using a tm symbol next to thier name on the site, but they have not registered it with the US trademark office.

As far as I know, there are basically two ways of getting a trademark: the first is by registering and the second is by using something commercially long enough for it to become clearly associated with a company or a product. The first kind of trademark is denoted by having an R inside a circle whereas the second is denoted with the small tm symbol.

In other words:
(R) = Trademark through registration
tm = Trademark through established use

Using the tm symbol in the press release is consistent with their position because they're saying that they have become associated with the name 'Fedora'. They can have a trademark claim to the word even when they haven't registered it.

Disclaimer: IANAL etc.