A rule is a set of couples (property : value) separated by ';' :

property1 : value1; /* Optional comments, as in C language */ property2 : value2; ...

Properties are reserved names.

Example : color font-family

Values are predefined names (colors), or integer or float numbers, optionally followed by a unit.

Example : 10mm 2.5em 16% magenta rgb(15%, 26%, 80%)