CIF - Chess Variant
C/CIF supports all chess variants if the variant can be described with MBN (Modified Betza Notation) and FBR (Formalized Board Rules). It is highly recommended to use the predefined value for the specification of the chess variant. Only if no predefined value exists (in case of a very seldom played variant) the variant may be given with a user defined identifier, which must not start with a colon, and must not contain spaces.
About the formal rules of the chess variants see on page Chess Variants.
A note about the usage of preceding colons for predefined values: this ensures an obvious difference between a predefined value and a user defined values. This means that a user defined value must not start with a preceding colon.