... that Did You Know (DYK) is the section on Wikipedia's Main Page that highlights our best new and expanded articles from the previous five days?

DYK features hooks—brief, catchy phrases or surprising facts—taken from these articles. An interesting hook attracts readers, encouraging them to click through to learn more. The DYK section is also a way to thank editors who create new content, and to encourage other editors to contribute to and improve that content and the encyclopedia as a whole. DYK entries appear on the Main Page for at least six hours. The section is updated as many as four times a day, and about 800 articles have appeared over the past month—that's more than 25 a day! DYK shows how the encyclopedia continues to evolve, and how editors are constantly adding fascinating new content.

The DYK program has been running for more than four years; among its editors are prolific contributors who have been responsible for hundreds of these snippets of information. You too can nominate an article at the DYK suggestion area.

Under DYK rules, all material must have been created over the past five days. Two kinds of article are eligible—new articles and articles that have been expanded at least fivefold. In either case, they should have 1,500 characters or more of main-body text (that is, excluding such material as references, lists, tables and infoboxes).

Strict adherence to the Manual of Style is not expected, but nominated articles do have to meet notability standards, be written in a neutral point of view, and have no maintenance tags. In the hook, shorter phrases are preferred, the information must be fully referenced with an inline citation, and the article content must not be misrepresented. Content forks of existing articles are ineligible.

DYK made its first appearance on the Main Page on February 22, 2004. The hook here was somewhat ironic: "Did you know that a pencil sharpener 'is a device for sharpening a pencil's point by shaving the end of the pencil'? Well, OK, you probably did." The pencil sharpener article had been created and developed by Raul654, an editor who had been on Wikipedia for only six months and is now a bureaucrat and the Featured article director. So great things grow from small beginnings on Did You Know!

As the DYK program has grown in significance, a number of innovations have been added. From November 2004, article creators have been formally recognized for their efforts. From January 2006, DYK notifications have been added to article talk pages. And from May 2006, nominators have been credited.

There is a DYK Hall of Fame and an unofficial list of the most prolific DYK contributors. Editors are awarded medals after 25, 50 100, and 200 DYK contributions. Blnguyen tops the list as the only editor to have created or expanded more than 200 articles. Blnguyen's DYKs include the revelation "... that Bobby Pearce won the single sculls at the 1928 Summer Olympics despite stopping mid-race for a passing flock of ducks".

Piotrus, Ghirlandajo, ALoan, IvoShandor, Yomangani, TonyTheTiger, Carabinieri, Tim1965, Wetman and P.K. Niyogi have all contributed over 100 new or expanded articles. When nominations are included, at least six editors have surpassed 200 total contributions—this group is led by Piotrus and includes Ghirlandajo, GeeJo, Blnguyen, ALoan, and PFHLai. Piotrus's many contributions include the fact "... that a part of Rawa River in Silesia is currently so polluted it is officially classified as a sewage channel". Wikipedians are urged to forgo the temptation to bathe in it.

DYK is also one of the three elements of the "Triple Crown" rewards for contributing DYKs, Good articles, and a piece of Featured content. On 30 April, following the promotion of his 15th Featured article—the 1960 South Vietnamese coup attempt—Blnguyen became the third recipient of the "Alexander the Great edition triple laurel crown" for contributing more than 15 DYKs, 15 Good articles, and 15 Featured articles. Cirt and Awadewit are the editors who have previously received this award. Cirt's Main Page gems include the tidbit "... that the 1937 Western fiction book Buckskin Brigades was Scientology founder L. Ron Hubbard's first published novel".

Nominations are submitted at the DYK suggestion area. The suggestion area is organized by nomination date, which means either the date the article was created or the date its fivefold expansion began. The nominator writes a hook of fewer than 200 characters that presents an unusual or interesting fact to follow the words "Did You Know ..."; for example, this April Fool's Day we featured the hook "Did you know ... that in a few villages and towns of southern France and Spain it is illegal to die?, and that there are attempts to have the same law in a town in Brazil?"

Other editors review the list of suggestions to ensure that all of the requirements are met and that the hook has an inline citation. It's important to keep an eye out for any comments these editors leave where an article needs attention. Around the fifth day after the creation or expansion started, five to eight articles that meet the criteria are moved from the suggestion list to a staging area. Administrators update the Main Page from this staging area every six hours or so. The administrators announce on the article's talk page that the article was displayed on the Main Page, and credit the nominators and major contributors.

Finally, did you know ... that no head or lead administrator runs DYK? Rather, because DYK promotion occurs around the clock, a large group of dedicated administrators takes care of the process.