Another one about Bren Gun markings

Hello

Im trying to help out a friend of mine about some markings on a Bren Gun Mk1

He wonders about a letter that stands in front of the serial number.
it says: C 7768 (dont remember the exact numbers)
Any one knows what the "C" stands for?

We know its manufactured in 1940, and ended up in norway during the caotic days of retreat in may 1940 in the northern parts of Norway.

Hope someone knows.

Michael

 

As far as er have figurer out it was used A, B, and C(maybe others aswell)
Bur we havent manager to fine out if there is a meaning to The letter.(which i suppose it is, why pur it there if not)

 

It's a serial-number prefix issued in blocks , 'C' denotes Enfield-built.

 

Thanks for the answer.
Guess "A" and "B" is for the australian production and the canadian.