Who are the Hash House Harriers?

Stolen shamelessly from the rec.running FAQ.

The Hash House Harriers is a running/drinking/social club which was started by bored expatriates in Kuala Lumpur, Malaysia in 1938. ("Hash House" is the nickname of the restaurant/bar to which they retired for food and beer after a run). Hashing is based on the English schoolboy game of "Hare and Hounds"; a Hash is a non-competitive cross-country run set by one or more runners called hares. The hares run out in advance of the other runners (the pack of hounds), and set a course marked by white flour, toilet paper, and/or chalk marks.

Don't be shy about hashing - if you've half a mind to join the hash, that's all you'll need!

Hash Rules

1. A HASHMARK is a splash of flour used to mark the trail. The pack should call out "On-On" when they see a hashmark. Blasts on horns, whistles, and other noise makers are encouraged. Hounds asking "RU?" (are you on trail?) of the FRB's (Front-Running Bastards) should be answered "On-On", which means they are on trail, or "Looking", which means they`ve lost the trail.
2. ARROWs, or several closely spaced hashmarks, are used to indicate change of trail direction. Hound should use arrows different from those used by the hares as necessary to assist hounds further back in the pack.
3. A CHECKMARK is a large circled X, or a circle with a dot at its center (fondly known as a "Titty Check"). Checkmarks indicate that the trail goes "SFP"; that is, the pack must search for true trail. Hounds should call out "Checking" when they see a checkmark. (Checking IS NOT Looking!)
4. A Backtrack is three lines chalked or drawn in flour across the trail, indicating a false trail. The pack, upon encountering a backtrack, calls out "On-Back" or "Backtrack", and goes back to the last checkmark to find true trail. Sometimes a hound will draw an arrow with a backtrack sign at the checkmark to identify the false trail for the rest of the pack.
   A CHECKBACK is a devious variation of the checkmark/backtrack. A checkback is a CB followed by a number. For example, a "CB 5" means to backtrack five hashmarks, then look for true trail as one would at a check. Also known as a COUNTBACK.
   A WHICHWAY is two arrows, only one of which points toward true trail; no hashmarks will be found in the other direction.
5. Tradition requires a DOWN-DOWN (chug-a-lug) of a beer after a hasher's virgin hash, naming hash, and other significant occasions, e.g., 25th hash, 50th hash, etc. A Down-Down is also in order for hares, visitors, and for any other reason that can be thought up. While frowned upon as "alcohol abuse", it is permissible for non-drinkers to pour the beer over their head; a soda Down-Down may also be elected. The primary consideration of the Down-Down is that once the mug leaves the drinker's lips, it is turned upside-down over the head.
6. THERE ARE NO RULES.