This Recommendation defines features of the Specification and Description Language that make the language practical to use. The features defined in this document cover the shorthand notation and annotation for the language, which is defined further in the other Recommendations of the ITU-T Z.100 series. Together with Recommendations [ITU-T Z.100], [ITU-T Z.101], [ITU-T Z.102], [ITU-T Z.104], [ITU-T Z.105] and [ITU-T Z.106], this Recommendation forms a reference manual for the language.