What is "letterboxing"

n. An outdoor hobby in which participants attempt to locate small boxes hidden in public places. vb. (present participle of letterbox English)

Letterboxing is an outdoor hobby that combines elements of orienteering, art, and puzzle solving. Letterboxers hide small, weatherproof boxes in publicly accessible places (like parks) and distribute clues to finding the box in printed catalogs, on one of several web sites, or by word of mouth. Individual letterboxes contain a notebook and a rubber stamp, preferably hand carved or custom made. Finders make an imprint of the letterbox's stamp in their personal notebook, and leave an impression of their personal signature stamp on the letterbox's "visitors' book" or "logbook" — as proof of having found the box and letting other letterboxers know who has visited. Many letterboxers keep careful track of their "find count".

Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes (black bars) above and below it; these mattes are part of the image (i.e., of each frame of the video signal). LBX or LTBX are the identifying abbreviations for films and images so formatted. The term refers to the shape of a letter box, a slot in a wall or door through which mail is delivered, being rectangular and wider than it is high.

Letterboxing may refer to:

• Letterboxing (filming), the practice of transferring film shot in a widescreen aspect ratio to standard-width, resulting in a letterbox
• Letterboxing (hobby), outdoor orienteering game