I don’t have a lot of T-Shirts anymore, but my favourite is probably one from a youth club in eastern Germany with Boss “MyName” (but the wrong spelling) on the back, and the logo of my late father’s long bankrupt company as a sponsor on the front.
It’s funny, but more in a nostalgic way.
Your instance is the address behind the @. So yours is lemmy.world, theirs is, fittingly, yiffit.net.