DOMESDAY BOOK. It consists of about 2 million words, written in black and red ink. Its 888 leaves are made of parchment, or the skins of between 500 and 1,000 sheep. Its language is abbreviated Latin incomprehensible even to classics graduates without special training. Its script is called ``Caroline minuscule.'' It was compiled -- a matter of considerable current celebration in Britain -- exactly 900 years ago.

THE year of the Norman Conquest of England, 1066, is the one date known to every British schoolchild. The brief reign of the last Anglo-Saxon King, Harold, ended at the Battle of Hastings, and William the Conqueror initiated a century of Norman domination. By the end of 1986 it seems likely that another date will also be impressed on Britain's collective memory: 1086, the year in which the survey of some 37 counties, or 13,418 named places, was carried out, decreed by William at his court in Gloucester at Christmas 1085.

This comprehensive accounting of who owned what in England, and how much everything was worth, rapidly assumed mythical status. Actually in two parts -- known as ``Great Domesday'' (pronounced ``DOOMS-day'') and ``Little Domesday'' -- the book acquired its ominous-sounding nickname about a century after its compilation. The name indicates a link in the popular mind between its ``unalterable'' decisions and those expected of the ``Last Judgment.''

Throughout its 900-year existence, Domesday Book has been held in extraordinary awe. It has gone from being a practical document of royal power to a museum piece, though even in modern times it has occasionally been invoked as admissible evidence in courts of law, generally in cases of land dispute. (The most recent land case was in 1960.)

The Victorians invested it with an aura of romance, and a century ago were the first to recognize a Domesday anniversary -- its 800th. But their modest series of lectures and documentary exhibitions was nothing compared with the abundance of exhibitions, events, publications, laser displays, fireworks, balls, conferences, processions, joustings, lectures, trips, commemorations, competitions, fairs, performances, reconstructions of Norman strongholds, walking tours, heritage weekends, medieval mystery plays, investigations of family trees, medieval music concerts, pageants, commemorative stamp issues, souvenirs, resource packets for schools, videos, and computerized investigations going on all over England this year.

But it is not all winsome commercialization. The fact is that, at the center of it all, there lie the rather sober-looking pages of Domesday itself, glass-cased in the specially staged main exhibition at this unique document's permanent London home, the government's Public Record Office. The book has been rebound (partly to make possible a new facsimile edition by Alecto Historical Publications) in tawed pigskin and quarter-cut English oak boards. Instead of being in the traditional two volumes, Little Domesday has been divided into three parts and Great Domesday into two. This has been done, say its guardians, ``for conservation reasons'' -- perhaps to avoid overcompression of the pages. Indignant chronicler

The exhibition's organizers have produced some fine entertainment, including modern parchment-makers at work, a tableau of a plowman and his ox, and two intriguing ``animated'' figures. Actually, only their heads are ``alive'' -- a film of actors' faces, emoting impressively, is projected on three-dimensional modeled heads. One represents William severely announcing his survey; the other is a monk from Peterborough, author of part of the ``Anglo-Saxon Chronicle,'' a commentary on life during that time. Quoting his own written English words, his face is twisted by disapproval of the king's actions. After all, as one of the exhibition's wall texts observes, Domesday Book was ``the obituary of the Anglo-Saxon state.''

``He sent his men,'' wrote this chronicler, ``all over England into every shire and had them find out how many hundred hides there were in the shire, or what land and cattle the king himself had in the country, or what dues he ought to have in 12 months from the shire. Also he had a record made of how much land his archbishops had, and his bishops, and his abbots, and his earls, and . . . what or how much everybody had who was occupying land in England, in land or cattle, and how much money it was worth. So very narrowly did he have it investigated, that there was no single hide nor a yard of land, nor indeed (it is a shame to relate but it seemed no shame to him to do) one ox nor one cow nor one pig which was there left out, and not put down in his record: And all these records were brought to him afterwards.'' There, already, is the Domesday ``awe,'' though his description of its comprehensiveness is certainly exaggerated. The survey concentrates largely on rural England. Two major cities, London and Winchester, were, in fact, omitted. Maybe the king was curious

The longstanding myth of Domesday Book's irrefutability is strangely at odds, also, with the fact that much of its detail must have been quickly out of date. Take the entry for Wisley, Surrey, for example (notable because it was one of the few places left with an English, rather than a usurping Norman, tenant-in-chief):

Oswald holds WISELEI himself. He held it himself from Earl Harold. Then it answered for 3 hides, now for 1 hides. Land for 2 ploughs. In lordship 1; 4 villagers and 4 smallholders with 2 ploughs. A church; 2 slaves. A mill at 10s; meadow, 6 acres; a fishery at 5d; woodland at 6 pigs. Value before 1066, 40s; now 60s.

Virtually everything in this item would have changed in a very few years.

Why did William order the survey made? Historians have promoted a variety of theories (they've had a few centuries to work at it). Today, the tendency is to believe that they all have a point: Domesday was a record of ownership, a feudal statement, a record of the country's assets, and a fiscal statement. Elizabeth M. Hallam, author of the newly published ``Domesday Book Through Nine Centuries,'' adds a further reason -- ``to satisfy the king's curiosity.'' Why not?

Dr. Hallam's book is a scholarly discussion of Domesday's history. She places it in the context of other surveys of its time, but concludes that it still ``has special qualities.'' In France, she points out, no comparable royal survey of any scope was made until 1204, and it was only an outline list taking seven years to complete. Domesday was compiled with exceptional speed: The actual survey is thought to have been completed by the end of 1086. Little Domesday was also finished by then, and Great Domesday, though actually never finished, was left as it now is by the end of 1087. Few fiscal records, Dr. Hallam observes, rise from being merely ``a pragmatic exercise in the gathering of information into a `most venerable monument of antiquity.' '' Winchester's slant on Domesday

One of the extra pleasures afforded by all the 1986 ballyhoo about this monument is that it provides an excuse for a visit to the city of Winchester. A delightful exhibition is staged here in the 13th-century Great Hall. Set out like a Norman encampment, this show offers its own slant on Domesday and its times. It vividly portrays how the Normans replaced the English aristocracy throughout the country. It shows the peppering of the land with Norman castles and the later flowering of magnificent Norman church architecture (take a walk down the road to Winchester Cathedral, and you see noble examples of the style in the transepts and crypt). It presents a tableau of the scribes writing Great Domesday. This, finally, is the point of the exhibition: It was in Winchester that Great Domesday is thought to have been written down. It was certainly kept here from the late 11th to the early 13th century, in the Royal Treasury. So Winchester can claim Domesday as a proud part of its heritage as justifiably as any place in the land. Practical information

Exhibitions: ``Domesday 1086 -- 1986'': Public Record Office, Chancery Lane, London, through Sept. 30. ``Domesday 900 Winchester'': The Great Hall, Winchester, through Nov. 1. Books: ``Domesday Book Through Nine Centuries,'' by Elizabeth M. Hallam (available in the US at the end of May from Thames & Hudson, 500 Fifth Avenue, New York, N.Y. 10110; $24.95). ``The Domesday Book: England's Heritage, Then and Now,'' edited by Thomas Hinde (English Tourist Board, 14.95). ``The Children's Book of Domesday England,'' by Peter B. Boyden (Kingfisher Books, 4.95). ``Domesday: 900 Years of England's Norman Heritage'' (official publication of National Domesday Committee, 3).