Not only was the cache of secret U.S. military reports released by WikiLeaks Sunday explosive in nature, but the sheer volume of data in the 75,000 reports and in the 91,000 total reports that make up its Afghan War Diary led the site’s editors to publish a long, comprehensive reading guide (see jump) to help users understand what they were trying to digest.

Afghan War Diary allows users to browse through the mountains of data by type, category, region, affiliation, date, and severity, as well as by drilling down into several subcategories. For example, under type, readers can choose from air mission, counter insurgency, criminal event, detainee operations, enemy, enemy action, explosive hazard, friendly action, friendly fire, non-combat event, suspicious incident, unknown initiated action, and other.

WikiLeaks also teamed up with three media partners in an effort to maintain the integrity of its initiative: Der Spiegel, The Guardian, and The New York Times.

From the introduction to Afghan War Diary:

The Afghan War Diary is an extraordinary secret compendium of more than 91,000 reports covering the war in Afghanistan from 2004-10. The reports describe the majority of lethal military actions involving the United States military. They include the number of persons internally stated to be killed, wounded, or detained during each action, together with the precise geographical location of each event, the military units involved, and major weapon systems used.

The Afghan War Diary is the most significant archive about the reality of war to have ever been released during the course of a war. The deaths of tens of thousands are normally only a statistic, but the archive reveals the locations and the key events behind each most of these deaths. We hope its release will lead to a comprehensive understanding of the war in Afghanistan and provide the raw ingredients necessary to change its course.

Most entries have been written by soldiers and intelligence officers listening to reports radioed in from front-line deployments. However the reports also contain related information from Marines intelligence, U.S. embassies, and reports about corruption and development activity across Afghanistan.

We have delayed the release of some 15,000 reports from the total archive as part of a harm-minimization process demanded by our source. After further review, these reports will be released, with occasional redactions, and eventually, in full, as the security situation in Afghanistan permits.

From the reading guide:

Most of the messages follow a preset structure that is designed to make automated processing of the contents easier. It is best to think of the messages in the terms of an overall collective logbook of the Afghan war. The AWD contains the relevant events, occurrences, and intelligence experiences of the military, shared among many recipients. The basic idea is that all the messages taken together should provide a full picture of a day’s important events, intelligence, warnings, and other statistics. Each unit, outpost, convoy, or other military action generates report about relevant daily events. The range of topics is rather wide: Improvised Explosives Devices encountered; offensive operations; taking enemy fire; engagement with possible hostile forces; talking with village elders; numbers of wounded, dead, and detained; kidnapping;, broader intelligence information; and explicit threat warnings from intercepted radio communications, local informers, or the Afghan police. It also includes day-to-day complaints about lack of equipment and supplies.

The description of events in the messages is often rather short and terse. To grasp the reporting style, it is helpful to understand the conditions under which the messages are composed and sent. Often, they come from field units that have been under fire or under other stressful conditions all day and see the report-writing as nasty paperwork that needs to be completed with little apparent benefit to expect. So the reporting is kept to the necessary minimum, with as little type-work as possible. The field units also need to expect questions from higher up or disciplinary measures for events recorded in the messages, so they will tend to gloss over violations of rules of engagement and other problematic behavior; the reports are often detailed when discussing actions or interactions by enemy forces. Once it is in the AWD messages, it is officially part of the record — it is subject to analysis and scrutiny. The truthfulness and completeness especially of descriptions of events must always be carefully considered. Circumstances that completely change the meaning of a reported event may have been omitted.

The reports need to answer the critical questions: who, when, where, what, with whom, by what means, and why. The AWD messages are not addressed to individuals but to groups of recipients that are fulfilling certain functions, such as duty officers in a certain region. The systems where the messages originate perform distribution based on criteria like region, classification level, and other information. The goal of distribution is to provide those with access and the need to know all of the information that relevant to their duties. In practice, this seems to be working imperfectly. The messages contain geo-location information in the forms of latitude-longitude, military grid coordinates, and region.

An especially helpful reference to names of military units and task forces and their respective responsibilities can be found at http://www.globalsecurity.org/military/ops/enduring-freedom.htm.

The site also contains a list of bases and airfields http://www.globalsecurity.org/military/facility/afghanistan.htm. Location names are also often shortened to three-character acronyms.

Messages may contain date and time information. Dates are mostly presented in either U.S. numeric form (year-month-day, e.g. 2009-09-04) or various Euro-style shorthands (day-month-year, e.g. 2 Jan 04 or 02-Jan-04 or 2jan04 etc.).

Times are frequently noted with a time-zone identifier behind the time, e.g. “09:32Z.” Most common are Z (Zulu Time, aka UTC time zone), D (Delta Time, aka UTC plus four hours), and B (Bravo Time, aka UTC plus two hours). A full list off time zones can be found here: http://www.timeanddate.com/library/abbreviations/timezones/military/.

Other times are noted without any time zone identifier at all. The Afghanistan time zone is AFT (UTC + 4:30), which may complicate things further if you are looking up messages based on local time.

David Leigh, The Guardian‘s investigations editor, explains the online tools they have created to help you understand the secret U.S. military files on the war in Afghanistan: http://www.guardian.co.uk/world/datablog/video/2010/jul/25/afghanistan-war-logs-video-tutorial.