Scalar Data Constants

For extensible scalar data constants, a service-provider vendor can define new values in a specified range. Because most data constants are DWORDs, the range 0x00000000 through 0x7FFFFFFF is typically reserved for common future extensions, while 0x80000000 through 0xFFFFFFFF is available for vendor-specific extensions. The assumption is that a vendor would define values that are natural extensions of the datatypes defined by the API.