Food label laws

If we look up The English Oxford dictionary for the word Meat, the response will be "The flesh of an animal" so you would be forgiven in thinking that should you buy a sausage that says "contains 50% meat" then you would be getting a sausage where the meat content of the sausage id 50%. Not so! Likewise, when is fresh not fresh, what about homemade? what are the rules to define homemade and when is organic not organic, I'll spend a few moments helping you get through this mind field to help you truly understand what your are buying!