The World Wide Web Consortium (W3C) XML 1.0 Recommendation defines enumerated types (notations and enumerations) and a set of tokenized types. These types are referred to as primitive types in this Microsoft® XML documentation.
The primitive types include the following, defined in Section 3.3.1 of the W3C XML 1.0 Recommendation.
| entity | Represents the XML ENTITY type. | 
| entities | Represents the XML ENTITIES type. | 
| enumeration | Represents an enumerated type (supported on attributes only). | 
| id | Represents the XML ID type. | 
| idref | Represents the XML IDREF type. | 
| idrefs | Represents the XML IDREFS type. | 
| nmtoken | Represents the XML NMTOKEN type. | 
| nmtokens | Represents the XML NMTOKENS type. | 
| notation | Represents a NOTATION type. | 
| string | Represents a string type. | 
XDR Schema Data Types Reference | XDR Schema Data Types | Supported Data Type Conversions | XDR Schema Developer's Guide | XML Schema Reference