/* Standard Observer, used in the measurementType tag */
 typedef enum {
     icStdObsUnknown               = 0x00000000L,     /* Unknown observer */
     icStdObs1931TwoDegrees        = 0x00000001L,     /* 1931 two degrees */
     icStdObs1964TenDegrees        = 0x00000002L,     /* 1961 ten degrees */
     icMaxStdObs                   = 0xFFFFFFFFL      /* enum = 4 bytes max */
 } icStandardObserver;