This Rule Would be:
No Off-site links unless it is approved by a moderator and/or an admin.
This means that if you put off-site links in your post, then your post gets deleted unless it is approved.
Reason 1:
This is to avoid scam websites, it is also to protect from disturbing/annoying websites, because there have been incidents on other fandom wikis where it would take you to websites like "free v-buck generator."
Reason 2:
It could protect from annoyances. There have been multiple occasions in which I was working on a page and it was wiped out because of some meme link.(specifically joke levels.) This has costed me a lot of coding and work.
This is why external links need to be removed.