Oh ... you haven't? Perhaps a further explanation is in order.
You can't really talk about the increasingly popular "Red Dress Run" phenomenon without first talking about hashing, and you can't really do hashing justice without a lengthy treatise on its history which was originated by Brits in Kuala Lumpur during the late 1930s and now exists in the form of thousands of hashing clubs worldwide comprising hundreds of thousands of runners, or hashers.
Suffice to say, hashing in its present form is not too different from what it was in its early days: groups of runners follow a marked (but unknown) trail though a given area a park, a downtown area, anywhere really. The routes are usually about five miles long; sometimes longer, sometimes shorter.
Teams of "hares" plot and mark out the trail using a series of symbols drawn in chalk on the pavement, or by small lumps of flour in rainy weather or colored Kool-Aid in snow.
Hashers start from a designated start point and go from there, finding their way from point to point by way of the symbols. The scrawled marks tell the hashers if they're heading in the right direction, more or less, although they're rarely that straightforward. A circle divided in quarters, for example (called a "check"), indicates that (lucky you) the trail can go in any direction from that point, so take your pick and hope you're right.
Sections of the trail often purposefully end in dead ends, indicated by a "turn around; you're lost" symbol. When a hasher thinks he or she is on the right track, they yell out "On-on!" and everyone else follows. The idea is that the faster runners will expend all their energy blazing the correct trail, allowing the slower runners to catch up so that everyone pretty much reaches the end (usually at a drinking-and-eating establishment) at the same time.
Why is it called "hashing," you might ask? It all goes back to the origins of the uh, sport: many of the earliest hashers in the Kuala Lumpur group were members of a club called the Selangor Club, and "Hash House" was the name of the bachelor's quarters across the street from the club. The group became known as "the Hash," and named their outings "hash runs" and the rest is history.
Hashers by and large tend to be fun-loving sorts of people to put it mildly. Beer figures prominently in the events, both during and after the hashes. Hashers often bestow good-naturedly raunchy nicknames for each other (that are pretty much unprintable here, sorry!), and mercilessly toast one another especially newcomers at their post-hash bashes.
Individual hash groups often think up different twists and variations on the basic hash theme, and that was how the red-dress run was born about 15 years ago.
Credit for the red-dress thing goes to the San Diego Hash House Harriers. It seems that one evening after a bout of revelry, a group of the San Diego hashers ended up in a hot tub. The hot-tubbers were joined by a woman (not a hasher) who was wearing a red dress and not much else, as revealed by the bubbling action of the hot tub.
Anyway, the female hashers weren't too keen on the attention their dates paid to the red-dress woman. They got their revenge at the next hash, when they and a few of the male members showed up in red dresses and required everyone (especially the ogling perpetrators) to run the hash in red dresses. The stunt evolved into a popular yearly event, and soon spread as a tradition to hash groups around the world.
From Adelaide, Australia to Washington D.C., from Frankfurt to Beijing, men and women don their running shoes and their finest red frocks, sheaths, gowns and skirts and take to the streets, drawing stares of bewilderment and admiration from passers-by and bystanders. As with all hashes, the goal is fun and beer, but everyone will admit that the red dresses add that extra touch of class.
For the moment, red dress runs are mostly limited to local hashes, but it won't be long before it catches on in the mainstream. Runs with a reputation for craziness like San Francisco's annual Bay to Breakers are already great places for otherwise normal runners to indulge their zany side, and more events are sure to follow.