Scope/Objective Recommendation ITU-T Z.103 defines the shorthand and annotation features of the Specification and Description Language. Together with Recommendations ITU-T Z.100, ITU-T Z.101, ITU-T Z.102, ITU-T Z.104, ITU-T Z.105, ITU-T Z.106 and ITU-T Z.107, this Recommendation is part of a reference manual for the language. The language defined in this document covers features of the language not included in Basic SDL 2010 in Recommendation ITU-T Z.101 or Comprehensive SDL 2010 in Recommendation ITU-T Z.102. Features defined in this Recommendation either do not have their own abstract grammar and are transformed to concrete grammar defined by Recommendations ITU T Z.101, ITU-T Z.102 and ITU-T Z.104 (and ITU-T Z.107 for object oriented data), or are annotations with no formal meaning. Coverage The Specification and Description Language has concepts for behaviour, data description and (particularly for larger systems) structuring. The basis of behaviour description is extended finite state machines communicating by messages. Data description is based on data types for values and objects. The basis for structuring is hierarchical decomposition and type hierarchies. A distinctive feature of the Specification and Description Language is the graphical representation. This Recommendation covers the features of the language such as shorthand and alternative graphical concrete syntax and macros that make SDL 2010 easier and more practical to use. The concrete grammar given is the graphical representation. The alternative textual programming representation is given in Recommendation ITU-T Z.106. This Recommendation does not provide a canonical syntax, but by applying the Model descriptions given a specification can be transformed to Comprehensive SDL 2010 defined in ITU-T Z.102, or (if no Comprehensive SDL 2010 features are used) to Basic SDL 2010 as defined in SDL 2010. It should be noted that in both Basic and Comprehensive SDL 2010 the details of expressions, data definitions and action language, are defined in Recommendation ITU-T Z.104 (and ITU-T Z.107 for object oriented data). Applications The Specification and Description Language is applicable within standard bodies and industry. The main application areas for which the Specification and Description Language has been designed are stated in ITU-T Z.100, but the language is generally suitable for describing reactive systems. The range of application is from requirement description to implementation. The features of the language defined in Recommendation ITU-T Z.103 are cumulative with, and rely on, the features defined in Recommendations ITU-T Z.101, ITU-T Z.102 and ITU-T Z.104 (plus ITU-T Z.107 for object oriented data). Therefore the language defined in Recommendation ITU-T Z.103 is practical for application to all kinds of real time systems (except if ASN.1 is also required in which case features defined in Recommendation ITU-T Z.105 should also be used, or if the specification needs to be in text only or interchange format in which case features defined in Recommendation ITU-T Z.106 should also be used).