Pretzels, or bretzels, were an important part of the cuisine in southern Germany at least since the 12th century. Apparently, shirking on the size of pretzels could be a problem. The photo here is from Heidelberg and represents a solution adopted nearly three centuries ago. The size and shape of a 'standard' pretzel, about 10" in diameter, was engraved onto the stones at the base of the central cathedral. If anyone suspected they were being cheated, they could place their pretzel on top of the engraving to verify if it was, in fact, large enough. This is an early example of the regulation of minimum quality standards.
BTW, pretzels in southern Germany (with a little butter) are delicious and Heidelberg is a lovely town to visit.