Unfortunately, many hotel's rules seem to be "open as few hours as possible" and "make the food as unappetizing as possible". There are, of course, good exceptions.
I've seen some hotels post guest's rules, though those seem to vary from property to property and I've never seen them enforced anyhow. But I have never seen a standard set of rules, such as something online. To some extent I imagine it really varies from location to location -- customs differ, amenities differ and target audiences differ. There have been a few good discussions here about the subject too.
I've never seen a published set of rules for the CL's. I would be in the camp of thinking that the hotels set their own rules for their CL. Some are staffed, some only have food re-fillers, some have nobody there during evening hours, some check each person that comes in the door to see if they belong and some have a free-for-all with people standing outside the door waiting for someone to open it and they rush in.
Please be sure to post any CL rules problems to the following thread, "Which marriott Brand & Loaction Did Not Honor an Anticipated marriott Reward Benefit for You?"
or click on the following link