Like i said, the problem is the interpretation. yes there is no restriction on text size as long as its legible but the actual British standard states name an postcode
ONLY.
No one wants Halfords in big letters on a plate, so yes, its okay for say a discreet 2mm logo
giving name and postcode but that
should be the only identifying mark.
The reason places twist it probably, is because its highly unlikely this detail of a numberplate is ever enforced that closely at the moment.
It will be eventually though. This whole standard was brought in, in an attemp to reduce car crime with suppliers having to register and adhere to regulations and obviously from what your saying it isnt being adhered to in the strictest sense across the board.
Expect it to tighten up soon though as VOSA are looking into clarifying all aspects of numberplates in relation to MOT passes and the logo is one of them.
There is a link to another DVLA document below which goes into a bit more detail of the current requirements and if you check the British Standard section at the end it clearly states that there shall be no other markings to the plate
http://www.dvla.gov.uk/media/pdf/lea...mberplates.pdf