How (or whether) to use a trade mark

[Mohamed_E]

I want to write a page on my definition of "achievement" in my hobby, and central to that is what I want to call the "Little Engine that Could" metric.

Checking Google I found the Little Engine that Could Home [penguinputnam.com], where I read:

THE LITTLE ENGINE THAT COULD, engine design, and "I THINK I CAN" are trademarks of Platt & Munk, Publishers, a division of Grosset & Dunlap, Inc., a member of Penguin Putnam Books for Young Readers

I have a limited understanding of copyright, but absolutely none of trade marks. Do I have to use the Trade Mark symbol every time I use one of the trade marked phrases? Worse yet, do I need permission to use these phrases?

[rogerd]

Mohamed_E, check with real lawyers for real advice, but trademarks have well-defined usage limits. That is, the trademark applicant specifies the products that the trademark covers. Thus, "Nova" could be a type of automobile, a prescription drug, and a fountain pen without conflict. In approving trademarks, and in resolving litigation, "probability of confusion" is a key criterion. Uniqueness enters into it; you might get away with Nova beer, but "Harry Potter" beer would probably be a no-no.

To search for a specific trademark, go to [tess2.uspto.gov...] - among other things, you'll learn what product/service areas are claimed by anyone currently using it. (Note that there could be others using a trademark that haven't been entered into the USPTO database yet.)

I'd avoid stepping on the toes of any well-financed trademark holder. Even if you are right, they can win a war of attrition.