(I haven't yet search for relevant posts or added a description - I just stumbled upon one post relevant to the UN, realised a tag should probably exist, and made it in the lowest effort way I could.)
Maybe this should be replaced with a tag on Intergovernmental organisations or Supranational organisations in general? Then that could also cover e.g. the WTO and potential future intergovernmental orgs.
Also, maybe neither this tag nor tags for those things should exist, since we already have tags for International relations and for Global governance. But it seems like the UN (or intergovernmental orgs more generally) is a sufficiently big deal to get its own tag?
This got 1 upvote, so I changed the name. But some googling quick suggested I should instead use the term International organizations, as that seems to be the superset containing both intergovernmental and supranational organization. But I've also included the latter terms in bold in the entry text.
It's possible that in future we should have an entry/tag for the UN as well, but if we only have one for now then it does seem to make sense to start with the much broader one (international organizations).