I'd never come across mild beer at all in my early drinking days in the 60s the Northeast- not part of the tradition of that area- weaker beer was known as 'Scotch' a a darker brew than the stronger 'Exhibition' beer from Newcastle Breweries, but certainly not as dark as mild- nor were the Vaux, Nimmo or Cameron equivalents.
The word 'bitter' in the context of beer was unknown in that area and Geordie lads moving south were given a lot of respect when they ordered a pint of Scotch!
Aware of this language problem, I remember asking just for a 'pint please' at the Swan Inn, on the riverside at Twickenham about 1964, only to be further confused when the barman said- 'do you want bitter
or beer?'    - 'beer' = mild at that pub.
Didn't mind Shepherd Neame's mild when I moved to Kent, but the Master Brew was magic, a lovely hoppy beer- 2013 version is a pale shadow of that...