Yes I agree, and the TSO I spoke to mentioned the fact that you can have
dual labelling - but I did not raise this as he also said that in his career
he had not seen such a thing - probably following the reasons that you cite.
Interestingly I have seen glasses marked "568ml" and "570ml" in European
(non UK/Eire) countries.
I too have made enquiries about this and the advice I have received is as
follows:
The "pint" indication is mandatory. However the law doesn't explicitly ban
supplementarry metric indications. There is a principle in British law that
if something is not prohibited then it is allowed. In the event that
glasswear was submitted for approval for use in trade bearing both metric
and imperial it would only be rejected if the extra information made it
unclear such that it could be misread for example as meaning "1 pint + 568
ml".
I can't think of any reason why a glass manufacturer would bother about the
metric label unless there is a market for thier products in other countries
where they can be used but metric is required.
In conclusion therefore we can rule out glasses that just say "568 ml" but
we can't rule out "PINT" ... "568 ml"
Phil Hall
