This is root element of this document which contains name space definitions for the document elements. It's a referenced element. For detailed description, please refer referenced element doc. Description is not available. Contains the number which uniquely identifies the subclass. Contains the class number of which the subclass is a member. Contains the department number of which the subclass is a member. Provide an extension hook to customize MrchHrSclsRef. This type can hold a number of digits count 4.