In Germany you need to "buy" a brand or have it registered as a trademark. Then you can claim it as a brand. Otherwise it will be difficult if you do not have a company named like that that is a Ltd. or Inc. or whatever registered companies there may be. At least it needs to be registered.
When I last looked (about one week ago), cmsmadesimple.de was still available. So it must be a fresh registrar. Maybe it would be just enough to kindly ask him to release the domain --- if needed. But looking at Mambo and the brand conflicts there it might be a good idea to do some fundraising for making CMSMS (and maybe even that abbreveation) a brand or a trademark.
Maybe we should have a plugin like
this one. ;o)
Regards,
Nils