* Returns TRUE if the argument type has a plural style part sequence and semantics,
* for example UMSGPAT_ARG_TYPE_PLURAL and UMSGPAT_ARG_TYPE_SELECTORDINAL.
* Returns TRUE if the argument type has a plural style part sequence and semantics,
* for example UMSGPAT_ARG_TYPE_PLURAL and UMSGPAT_ARG_TYPE_SELECTORDINAL.