Formal description techniques are extensively used in ITU-T Recommendations
to describe system behaviour, structure and data, in order to produce
precise and unambiguous formal specifications, which are essential to
the quality of the Recommendations and their implementations.
Those descriptions are organized by formal language as follows:
Object identifiers are used to identify modules, attributes, functions, etc. in a
unique and universal way. Several tools and directories are available for that purpose:
Others...