It seems however that the point can be stretched on occasion – the Advertising Standards Authority Directorate in a recent ruling dismissed a complaint against a processed meat product packaged as “Lamb Stew” although – as was disclosed on the contents panel – the product occasionally contains mutton as well as lamb.  (Note that this ruling doesn’t allow your friendly neighbourhood restaurant to serve you mutton when you ordered lamb - the fact that the stew in question was a prepared and packaged product rather than a fresh one seems to have been critical to the ruling!). 

Buyer Beware!  Read the small print on the contents panel.