scope:

This International Standard defines a notation, Extended BNF, for specifying the syntax of a linear sequence of symbols. It defines both the logical structure of the notation and its graphical representation.

Extended BNF has applications in the definition of programming and other languages, as well as in other formal definitions, for example the commands to an operating system, or the precise format of data and results.

Examples of Extended BNF are given in clause 8.

NOTE - Like many other notations, Extended BNF can still be misused; thus it does not prevent someone from trying to define an unparsable or ambiguous language.