This standard provides the means to define and describe signals used in testing. It also provides a set of common basic signals, mathematically underpinned so that signals can be combined to form complex signals usable across all test platforms. The provision of language elements supports test signal descriptions for interoperability. 1 The numbers in brackets correspond to the numbers of the bibliography in Annex L. This standard is divided into seven clauses: — Clause 1 provides an introduction to this standard. — Clause 2 provides definitions of terms and lists abbreviations. — Clause 3 describes the structure of the STD standard. — Clause 4 specifies the signal modeling language (SML). — Clause 5 specifies the STD basic signal components (BSCs). — Clause 6 defines the test signal frameworks (TSFs). — Clause 7 describes the test procedure language (TPL) layer. This standard also contains the following annexes: a) Annex A provides the Signals Modeling Language that is used to construct the BSCs and the TSFs. b) Annex B provides BSC descriptions. c) Annex C provides dynamic signal model description, states, and state transitions. d) Annex D provides the interface definition language (IDL) description for the BSCs. e) Annex E provides a TSF. This framework provides a formal description of signals similar to the signals defined in IEEE Std 716-1995. It also serves to illustrate how complex test signal models can be built up from BSCs. f) Annex F provides the IDL description for the TSF provided in Annex E. g) Annex G defines the requirements for a carrier language. h) Annex H provides the formal TPL description. i) Annex I provides the extensible markup language (XML) description mapping signal models into XML descriptions. j) Annex J provides XML description mapping the TSF provided in Annex E into XML descriptions. k) Annex K provides a description of how ATLAS nouns and noun modifiers are supported by STD. l) Annex L provides a bibliography of related documents.