They do overlap often. Some of the most interesting caches I have found have been combinations of the two.

It's easy to determine if a cache should be a puzzle type when setting one. If there is a puzzle to solve at any point to find the cache, then it is a puzzle whatever else has to be done to retrieve the cache, including visiting multiple stages. There are cachers though that are more than capable of solving puzzles, but maybe are not capable, or just not happy to tackle a long distance multi to find a cache. Sometimes COs are good at giving distance info on cache pages through listed waypoints or by using the attributes, but not always.

I wouldn't make the rules stricter, but have thought about this in the past and came up with another, what I believe would be a good simple solution for groundspeak, which other people may of thought of too. That is have another cache type icon. Puzzle for puzzle, Multi for multi, and PuzzleMulti for the combinations. I cannot see it being implemented though because of the thousands of caches already out there that are in place on the existing icons.


A side note, has anyone come across any other caches with the same query? Do other cache types have to conform? I give Lair of the Lost Boys as an example. That one is not a straight forward letterbox. Are letterbox cache setting rules different to other types?