The code/@code shall not be null and shall have the values 'Opt-Out' or 'Opt-In' [SP-042] [SP-043] [SP-044] OCL (not self.code.oclIsUndefined()) and (not self.code.code.oclIsUndefined()) and self.code.matchesValueSet('1.3.6.1.4.1.12559.11.13.4.1', self.code.code, self.code.codeSystem, null, null)