Some tags are automatically created when a new child meta is spawned, including mod-only tags like featured and mandatory tags like discussion, as well as some ordinary tags like bounty, users, and rss.
Using Meta.Japanese as an example: if you look at the bounty tag there, you can see that it exists even though there are no questions there, since it asks you if you would like to create a tag wiki for it. On the other hand, the hypothetical asdfghjkl tag does not exist at all, and hence does not ask you about creating a tag wiki.
I would like to know which tags, like bounty, exist by default in the system. It would be particularly nice if this information was available in SEDE or the API, but if not, an answer here would work, too. Knowing this would help me know which tags on meta sites need to have tag wikis added to protect them from the script that deletes single-use tags after 6 months.
I could, I suppose, glean this information by inspecting the tag list on Hinduism's meta right after it launches, but I think it would be good to have this information on Meta.
EDIT: The post this one is allegedly a duplicate of is no longer accurate. At minimum, it claims that
delete is a tag that should be present on all child metas; however, as you can see at Meta.Japanese, there is no