Occassionally geocachers stumble upon a letterbox while searching for geocaches. When they do they may assume that what they found is a geocache (or terracache or some other version of the geocaching game). Geocaching involves the trading of trinkets whereas letterboxing involves the trading of stamp images. Your stamp may inadvertently end up traded out for another object. The geocacher means no harm because they are playing the game the way they know how, they may never have heard of letterboxing and don't know that letterboxers exchange stamp images not trinkets.

So one way to prevent your stamp from being traded out would be to educate those that stumble upon your letterbox.

• Short note: Leave a short eye-catching note in the box. Something that says: "Please do not take the stamp. Leave it in the box." You may also want to add a short blurb about what the letterboxing process involves: "Letterboxers exchange stamp images. Take an impression of the letterbox's stamp, leave an impression of your signature stamp." I personally would not leave a lengthy information sheet explaining all the intricacies of letterboxing folded up and tucked away in the box. Many people may assume it's a geocaching information sheet and they already know what geocaching is so they're not going to unfold the paper to see what's written on it. They also may not feel they have the time to sit and read a 250 word document on letterboxing. You want to get the most important information out to them....Do not take the stamp.

• Write on the back of the stamp: If there's room on the back of the stamp write: "Do not take. Leave in box." for added security. Caveat: ink will bleed over time on some rubber material. You may have to re-write on the back of the stamp when you do maintenance visits. Example of stamp with penned note on the back.

• Check geocaching.com: The other thing you might want to do to prevent your stamp from being traded out -- see what geocaches are nearby when you go to plant your letterbox. See: How can I tell if there are any geocaches near the spot I want to hide my letterbox? You might even consider planting within 528 feet (.1 miles, 161 meters) of the geocache because once a geocache is published no other geocache can be planted within 528 feet of that cache. If you plant say 350 feet away from the cache that insures that another cache will not be planted next to (or in some instances, on top or below) your cache.