So we don't need slashes in HTML anymore?

Is this for all / or just self-closing tags? When did this happen?

Technically, you never did need them. It was a bug in the FCC tests to require them. I believe most of these tests have been fixed now but you might run into one that got missed.

And yes, this is just for self-closing tags. If an element requires both an opening and closing tag (which most do) then the closing tag must always start with </.