Dave above is correct.
To make it even more complicated, there are state level and federal level marks. (For example, I never worked outside state boundaries, but held State TMs and State R for several things in both MA and MO.)
The R is registered in the USA at the Patent & Trademark office and require work, research and $. Provides nation-wide protection.
Anyone can use the TM symbol without actually registering. It puts people on notice that someone is claiming a name. e.g. DavidLMO TM David Laderoute.
Service marks add the new wrinkle - related to services, not physical products; e.g. Gardening by DavidLMO SM David Laderoute.
This entire post is Copyright 2016 by David Laderoute All Rights Reserved.
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Now please - Don't ask about PPAF