Spooky 👻 Halloween 🎃 Dark 🦇 Horror 🔪 Memes

Y

"w/" has been around forever, though it's a bit less common without the slash. Here's a random language forum post from 16 years ago commenting on how it's common which I found with a quick search, I'm far too lazy to put in more effort but I'm sure someone properly motivated could find older references or maybe even the full etymology.