I avoid eating Taco Bell's meats. A friend I used to work with told me that he once saw a case of the ground beef they used when that was the only meat they served, and its grade was really low - so low that it was marked "Not intended for human consumption."
I don't know if it's true or not, but I never thought of him as dishonest and never caught him being dishonest in anything else. I just can't ignore it though.
I often see this label on pet food which just means it isn't inspected properly. Also some 'edible' packaging may have it. Technically you can digest it. I doubt Taco Bell could get an exception from FDA and the likes, maybe corruption at the individual franchaise level?
That said, their beef is junk. I still eat it though, but I have low standards when it
Actually I don't think Taco Bell was owned by Pepsico or whatever big corporation owns it back then, so doing something like this was probably a breeze. ;)