I think it's admirable that you care enough to ask the question. Don't let anyone make you feel bad about doing it the right way!!! There are guidlines about things to not put in a cache...like food items or anything that smells like food, gum, mints, incence, scented candles and the like will smell good to animals and they will tear the cache apart to get to it! Also, many people cache with their kids, and do not appreciate sharp items like knives placed in there. They can be a problem. Just use your common sence..like someone else said above, there are all kinds of people caching, and you never know what someone will like or dislike...if they don't like it, they don't have to trade for it! It's that simple. So don't sweat it and have a good time! Cache on!