OS/VS COBOL supported the COBOL 68 Standard (LANGLVL(1)) and the COBOL 74 Standard (LANGLVL(2)). Enterprise COBOL supports the COBOL 85 Standard. In addition to the language differences between the COBOL 74 Standard and Enterprise COBOL, your OS/VS COBOL programs might contain undocumented OS/VS COBOL extensions.