The GetNextRevisionCode method of the ISPClientApplicationNoUI interface uses this enumeration from SchemaCompInterfaces.dll.
enum eRevisionInformation {
eriNoComment = 0,
eriError = 1,
eriNoFirstMajor = 2,
eriNoFirstMinor = 4,
eriNoNextMajor = 8,
eriNoNextMinor = 16
} eRevisionInformation;