[cmaggiulli]

I would argue that “no shirt, no shoes, no service” is not rule but rather a concise and simplistic phrase that communicates the spirit of the rule to a broad audience. The rule is that a human must have their feet, part of their lower and upper body covered or else they will be denied entry and/or refused service. The phrase is just a way to communicate that rule in a concise way

[moolcool]

That's kind of my point though. Written rules sacrifice specificity for brevity all the time, and it works for most reasonable people most of the time.