There is no rule, it’s simple logic! If you find a geocache, go to the cache page and log it as found. If it doesn’t have a page, how can you log it?
I am a "number ho" from way back, and this makes absolute sense to me. One smilie per page/event. No page, not a real cache. I only log caches I sign, and coins I see.
just my opinion, your results way vary.