[TeMPOraL]

It shows up on HN every now and then (though I wouldn't say it's very common). I use it when discussing potential spoilers for books/shows, because HN doesn't have a "spoiler tag".

[AnIdiotOnTheNet]

Before spoiler tags were a thing that BBs and forums implemented ROT13 was actually a fairly common way to avoid spoiling things.

[jessaustin]

I appreciate this practice. Here's a useful extension:

https://chrome.google.com/webstore/detail/rot13/bahejodllcom...