Difference between "Return" and "Warp"?

[Claviusnex]

Warp is a remnant from Alpha / Beta..
If you were stuck, you were told to use Warp as it's the same as return but no CD.

In other words, it shouldn't actually be in the game still..

It might have been left in as there are probably still code errors that will get players stuck. SE might not want it to be common knowledge and only used at the direction of support people but obscurity doesn't last long.