It seems a little absurd that trademarks can be used like this - I can understand for product names, and slogans, but surely if the words are different - then y

It seems a little absurd that trademarks can be used like this - I can understand for product names, and slogans, but surely if the words are different - then you're just trademarking the _idea_. So, if I get it right, if you refer to any meat as being white meat but not chicken, then you infringe upon the National Pork Board's trademark? Just checking, I'd never heard of the slogan 'til today (not from US).