Relax NG ISO/IEC 19757-2:2008 application/xml ISO/IEC 19757-2:2008 Information technology -- Document Schema Definition Language (DSDL) -- Part 2: Regular-grammar-based validation -- RELAX NG RELAX NG by Eric van der Vlist for O'Reilly (Free Documentation Licence). FOLiA set definition alpha application/xml EBNF ISO 14977:1996 text/plain ISO/IEC 14977:1996 Information technology -- Syntactic metalanguage -- Extended BNF XML Schema 1.0 application/xml XML Schema Part 1: Structures Second Edition