Man U is not a term United fans refer to themselves as. The term is only used by other supporters as a complete and utter insult to our club. The "u" is meant to be "you" by the rival fans.
An early example of its usage is this chant by West Brom fans: "Duncan Edwards is manure, rotting in his grave, man you are manure- rotting in your grave". The origin of "Man u" is a song to insult the dead Duncan Edwards.
Liverpool and Leeds fans copied this with their own man you /u versions to insult all of the lads who died at Munich.
"Man U Man U went on a plane Man U Man U never came back again"
"Man U Never Intended Coming Home" (if you combine the first letter of each word you get the word "Munich").
I hope this makes it clearer that saying man u is an insult, particularly to the older supporters and to see United fans using it now is shameful. I hope a few might read this, understand and spread the word.
So... Please stop using this term ever again
I know it isnt an article, it may have already been posted but I've only been here a few hours and I've seen the term used again and again