The Comprehensive Ruleset has now become the way things are done, but the use of the Codex is not obsolete. Indeed, the longevity of modern rulesets depend on them, as they are used to provide values, variables and constants used in conjunction with the rulset. For example, a Chalk Farm 1984 game played on the Podume and Cascade Values Codex 1981 will be a lot different from one played on the later 1988 Codex. The Codex is read avidly by the technical player keen on causing all sorts of mischief to their opponent, but it is important that any player knows his values. In International Competitions, a codex is prohibited from being taken into the play arena.
The Codices in current use are as follows:
All games are played with these values unless they are declared otherwise (which requires the permission of IMCS if it is a rankings competition).
The most colourful codex ever to be published is the Network Values Codex of 1955 as amended 1956. It has been nicknamed the 'Snood Codex' as it brought [snood play]? to the cutting edge of Mornington Crescent play for its short 4-year life. (See also: Snood.) Some of its values and recommendations still have a residual effect today, but it is a far cry from the 1957 final of the World Championships where Trellis twisted the snoods by 265 degrees and used the centrifugal gravity this caused to suck her opponent from his winning position on the District Line and forced him to pre-empt an Ongar denial, thus allowing Trellis a cross-diagonal under-strile, drawing up to Mornington Crescent with a magnificently tidy line velocity of +1.0.