There are a couple I have in mind. Like many techies, I am a huge fan of RSS for content distribution and XMPP for federated communication.
The really niche one I like is S-expressions as a data format and configuration in place of json, yaml, toml, etc.
I am a big fan of Plaintext formats, although I wish markdown had a few more features like tables.
Always? That’s my first reply. Bug of what? A flaired character has a different code than a standard one, so your files would be incompatible with any established tools like find or grep.
My bad, confused you with someone else.
You can always update them.