I suppose this is somewhat off-topic, but:

Did you know anyone can become a real estate agent, but “realtor” is copyrighted and only refers to a member of the National Association of Realtors? We didn’t!

I was actually reading a novel (Lovecraft Country, by Matt Ruff) where this came up.

The novel is largely about racism in the 1950s (with a Lovecraftian supernatural twist), and one of the minor characters is a black real estate broker. But because the National Association of Realtors did not admit black members at the time, this character had to refer to himself as a “realtist” rather than a “realtor.”