Yeah, I first learned about it from a friend who's into the 'Once Upon a Time' fandom, where it's more common. There's a lot of variations too.

I do know of one Drarry fic that uses a similar trope (soul mate markings, but no words) and that's A Tale of Woo by veritas03, which is a really good fic as well.

But now I want even more :)