The old cliché is that the only rule is that there are no rules. That is true for the art of letterboxing in many senses, although there is some common sense etiquette:
- Respect the land when hunting boxes and when hiding them. Don't place a box that requires people to tramp through sensitive wildlife or plant habitat to find it, for example. Warn hunters of possible hazards in the area of the box in your clue notes. Use common sense. If you have any doubts, ask the landowner or manager, or simply choose another location for your activities. Adopt the Leave No Trace principles of outdoor etiquette. Remember, some lands have restrictions on land use; know them and observe them.
- Don't publish or re-transmit other peoples' clues or stamp images without their permission.
- Repack and hide the thing as well or better than it was when you found it, in the exact place you found it. After finding it, try to be discreet when stamping up and re-hiding it, as if you were hiding your own box for the first time. When I find one, I usually carry it deeper into the woods to stamp up, so as to not give away its location to any passerby's, then put it back when I am done.
- Do not post clue solutions on the Internet or discuss how to solve clues in public. That spoils the fun for everyone else.
- Of course, do not violate the laws, rules, customs, and people or property rights wherever you conduct any activities.
- Take responsibility for the safety of yourself and your group. If you think the clues are taking you to an unsafe location, don't go there.