I believe links like this will be sorted automatically in Lemmy 0.18 but until then links are like this without the space between ] (

[!community@instance] (/c/community@instance)

!kde@lemmy.kde.social

Currently if the community hasn’t been discovered by your instance then you’ll get a 404 error like I just did, apparently it’s a known thing and you need to search for the community before accessing it, see here - https://github.com/LemmyNet/lemmy-ui/issues/1335