BYOP: An acronym for “bring your own pen.” Usually means the cache is too small to hold a pen or pencil. You must have one with you to sign the log.
Camo: Short for camouflage. Any attempt to make your cache container blend in with its surroundings. Common methods for camouflaging a cache include painting, wrapping with camo duct tape, gluing or attaching natural materials, or using containers that purposely mimic common objects, such as rocks, bolts etc.
CITO: An acronym for “cache-in, trash-out.” A specific type of event where geocachers gather to collect trash or unsightly debris and remove it from a park or other natural area. These events are organized to give back to the greater community and to present geocaching in a positive light to public land managers and fellow outdoors enthusiasts.
CO: An acronym for “cache owner,” the person who placed the cache.
DNF: An acronym for “did not find.” Often included in logs where the geocacher failed to find the log. If you see a string of these it the logs for a geocache, it either means the geocache has been muggled, and the CO should replace it or disable it, or that the geocache has a high degree of difficulty.
Geocoin: Decorative or commemorative coins stamped with the tracking number (see trackable).
FTF: An acronym for “first to find.” It means the finder is the first to find a particular geocache. Sometimes the cache owner leaves a FTF prize, a high-value piece of swag designed to reward the first finder.
Geocaching: To quote the online Miriam Webster: A game in which players are given the geographic coordinates for a cache of items which they search for with a GPS device.
Muggle: A person who does not geocache.
Muggled: The theft or removal of a cache, purposely or mistakenly, by a person who does not geocache.
Micro: A small geocache container. Generally too small to hold anything but a log and small items.
Nano: An extremely small geocache, usually about 1 cm or less. Log is typically a small strip of rolled-up paper that may require tweezers to extract.
Swag: The goodies placed in a geocache to reward the finder. The finder is expected to trade swag items, in other words, the finder may remove a swag item from the geocache only if he/she places another item in the geocache.
Smiley: The geocaching.com website replaces the geocache icon (on the map interface) with a smiley face when you find a cache. As a result, a “smiley” has become geocacher shorthand for a found cache.
TFTC: An acronym for “thanks for the cache.” A common salutation on either a paper or electronic log. A way to acknowledge the time and effort a CO spends in placing and maintaining the cache.
Trackable: A type of swag stamped with a tracking number that is registered on the geocaching.com webpage. A trackable is intended to be moved from cache to cache, rather than kept by the person who finds it. The tracking number is logged online so that the trackable owner can monitor its progress in fulfilling its mission (assigned by the trackable owner). The two most common trackables are geocoins and travel bugs.
Travel bug: any object attached to a metal tag stamped with a tracking number (see trackable).