In "Now for a feast" (20 December, pages 24-27), Jonathan Meades refers to "the trashing of the conjoined giant portakabins".
I am writing to point out that "Portakabin" is a registered trademark that may only be used to describe buildings manufactured by this company.

In order to protect our rights to the exclusive use of the mark, we must take active steps to discourage its use as a generic term. May I ask that, in any future cases of this kind, you use the term "portable building" or "relocatable building".

I do assure you that this is of considerable importance to us.

Postscript

Dick Ellershaw, trademarks officer, Portakabin, York.