My personal rule is to avoid factory farmed meat. 100% effective when buying for home, but I admittedly compromise when eating out, but by asking each time I plant the seed I hope. I do, as an omnivore, think everyone should see, and take some part in, raising, and slaughtering livestock before it becomes a staple of your diet. Meat comes from animals that died for you, not the store. Respecting that has more impact than blanket-avoidance in my eyes.
Having that tradition, that every Friday you don't eat meat, but fish is acceptable, seems to colour your perspective when thinking about what is being a vegetarian.
I'd rather have it clear that people use the right terms, since some will probably complain about being given only vegetables when there was fish available, whilst happily claiming they are vegatarian.
it's almost like claiming that you are vegan when you are vegatarian.