If anyone is wondering what it looked like while editing, here ya go: 
That is only true for the url
Anytime I've gotten a mention it has always been @x4740N@lemmy.world
I'd mention you as @Xusontha@is.buckodr.ink
And again the lemmy documentation doesn't mention u/
Edit: never mind I just realised I misread your initial comment and went on from that initial misreading
Sorry about that