Backus-Naur Form

Backus-Naur Form (BNF) is a format for context-free grammars. It’s often used as computer programing languages, protocols and documentation. It was created in 1950th by John Beckus together with ALGOL language. Nowadays one can find different variants of of BNF, such as Extended Backus–Naur Form (EBNF) and Augmented Backus–Naur Form (ABNF), it’s used in official specifications, manuals, textbooks, etc.