Manchester United fans

From Wikipedia:

The atmosphere produced by the fans has, however, been criticised at times. In 2000, comments made about sections of the Old Trafford crowd by the then-club captain Roy Keane, claiming some fans could not "spell football, never mind understand it" led to them being dubbed the "prawn sandwich brigade"

FULL DISCLOSURE: I am a Manchester City supporter, so United fans can suck it.

This sea of red was observed in the wildby an associate of
the Professor at the recent Man United vs Man City match.

Is that a period joke?