This document specifies a syntactic description language for describing the structure of binary data. It covers the representation of an SDL specification in plain text, the syntax of the SDL and the semantic rules of the SDL.

In scenarios where the usage or interpretation of the SDL are ambiguous or undefined, this document attempts to specify whether such a scenario is considered an invalid SDL specification or will result in undefined behaviour.

NOTE            While the SDL borrows from and contains some aspects of a general-purpose programming language, it is not intended, nor is it suitable, to be used for such a purpose. This is reflected in the fact that many concepts related to general-purpose programming languages are not addressed in this document. Examples of concepts considered irrelevant to the SDL and therefore not addressed in this document include storage of an SDL specification in a file, compilation, execution, input/output, execution environment and machine architecture.