Wow, the bulk of this post is devoted to patent and trademark law .... and nobody even quotes the appropriate TRADEMARK laws. (I did see a quote on Patent Law, I love that "one well-versed in the industry" part, seems the kids at USPTO have turned a blind eye to that on a number of patents, such as Jamison's cartridge patents and a bunch of software patents. But I digress)
From the USPTO website (and yes, you can look up filed applications on line)
A trademark is a word, phrase, symbol or design, or a combination of words, phrases, symbols or designs, that identifies and distinguishes the source of the goods of one party from those of others.
Is registration of my mark required?
No. You can establish rights in a mark based on legitimate use of the mark. However, owning a federal trademark registration on the Principal Register provides several advantages, e.g.,
constructive notice to the public of the registrant's claim of ownership of the mark;
a legal presumption of the registrant's ownership of the mark and the registrant's exclusive right to use the mark nationwide on or in connection with the goods and/or services listed in the registration;
the ability to bring an action concerning the mark in federal court;
the use of the U.S registration as a basis to obtain registration in foreign countries; and
the ability to file the U.S. registration with the U.S. Customs Service to prevent importation of infringing foreign goods.
When can I use the trademark symbols TM, SM and ®?
Any time you claim rights in a mark, you may use the "TM" (trademark) or "SM" (service mark) designation to alert the public to your claim, regardless of whether you have filed an application with the USPTO. However, you may use the federal registration symbol "®" only after the USPTO actually registers a mark, and not while an application is pending. Also, you may use the registration symbol with the mark only on or in connection with the goods and/or services listed in the federal trademark registration.
(emphasis mine)
So if noone else claimed it, Mark can run with it ...
Now back to the regular scheduled programming