Why are there etching in beer glasses?

apparently etching on the base of a beer glass, ie the carling glass which is laser engraved on the base improves the taste! might be a myth!

Also there is a CE stamp engraved to state the imperial measurement in the UK which is a legal mark to state the glass holds a pint.

http://en.wikipedia.org/wiki/Pint_glass

For fun you can have a pint engraved as well:

http://www.keepitpersonal.co.uk/engraved-beer-glass-traditional-pint-glass-p-742.html