Shirt sponsors.
They have become such an intrinsic part of modern football that whenever Valencia v Sevilla is on the idiot box, the very sight of both teams donning their pristine, sponsor-free garb is enough to make even the most casual football fan go "oh yeah, that's a bit odd."
It's weird for a professional team to not have a company's name emblazoned on the front of their shirt, but we at SportsJOE like weird. So much so that we've collated together 10 Liverpool and Manchester United jerseys from the past and removed their sponsors.
The question is, can you identify the sponsors we've removed from the jerseys? Take our quiz below to find out.
Brought to you by Ladbrokes.
