I never use the application names in any of my servers because I'm always worried about future trademark enforcement.
The Mastodon organization guidelines at https://joinmastodon.org/trademark say:
Do not use or register, in whole or in part, the Mastodon marks as part of your own or any other trademark, service mark, domain name, company name, trade name, product name, or service name.
When I search the database here for instances known to this server that contain "mastodon" in their domain names, I see over 1,800 server names. And it's unknown if they would consider "mstdn" to be a violation as well.
I wonder how far they will push this enforcement. A Mastodon server cannot change its domain name.

