I think most if not all managers of markets understand that other markets have different rules than theirs, but do your shoppers know? And have you ever updated them, in cooperation with your vendors?
Nearby markets should share rules so that they do not make their farmers follow different sets of rules for little reason. It’s amazing how many markets don’t even attempt to compare rules which makes it quite hard for vendors to remember which of their markets has rules against packing up early or who allows foraged items and who doesn’t. One of the main areas of contention among farmers is the amount of liability insurance that they are required to carry (when a market requires it); a farmer told me about three different levels of insurance that he was asked to carry, all of the markets within a few miles of each other.

http://www.twincities.com/stpaul/ci_24036424/farmers-markets-not-all-follow-same-rules