Can’t read Formatting_Functions information on codex

The red links mean there is no data available for those functions at this time.

Thank you.

Why doesn’t it just say that rather than imply I’m not allowed to see it?

It’s a wiki. That’s how wiki’s work. If you actually clicked one, you’d see “You’ve followed a link to a page that doesn’t exist yet.”, if you were logged into the wiki instead of being not-logged-in. Only logged in users can edit those pages.