I'm still using the full URL for internal links. There's @ for users and /c/ for subcommunities but it'd be nice if we could refer to exact threads and comments using just the part after the domain name for if that part ever changes again, it's changed once so far. It's just for archival purposes so that not all the links break in the future. Wikis support this too.

Like this.

Edit: I see that it is in fact implemented that's great!