a pattern specifying the allowable structure for each value in the attribute applicPropertyValues in the element <enumeration>. The attribute valuePattern must only be used when the attribute valueDataType has the value "string" (refer to default BREX rule BREX-S1-00135). The pattern follows the XML Schema regular expression rules as described in the specification "REC-xmlschema-2-20041-28 W3C Recommendation: XML Schema Part 2: Datatypes Second Edition (2004 Second Edition)".