!tankiejerk@lemmy.world is the syntax for linking to communities. I feel it’s used too rarely on Lemmy, leading to the slow propagation of information and few people using the unique features that make the lemmyverse navigable. I’d never manage to reach the communities I’m searching for if not for easy linking.
Will edit it in when I find more but this is Lemmy’s markdown tutorial. It covers a few items uniqueish to lemmy, especially cool are magnet links, but I’m not sure where they keep info about other unique features. Offhandedly, the only other thing I can think of is linking to profiles with @Gullible@sh.itjust.works. (This does ping the user, btw)
Edit: I got nothing, it’s impossible to find and/or doesn’t exist. No other option. But if someone else finds it, a link would be helpful.