It's funny to see how all the history has been scrubbed from the Wikipedia entry.
https://en.wikipedia.org/w/index.php?title=Lifeline_(FCC_pro...
This page - https://en.wikipedia.org/wiki/Irony_punctuation - has sarcasm ones (but I don't think any are as well known as the interrobang, which itself isn't exactly universally used... though personally I'm weird enough to have a keyboard shortcut to type it on my phone)
I'm not the only one‽
(Unrelated, do you work at Paradox? Or 3 letters in your username coincidental to their abbreviation?)
-- mikeSEA
Can you imagine "A Modest Proposal (/s)" ?