Unit System value

Why is the System value for US Survey Foot set to 1 in the units.def file, but set to 3 in the two different .h files?

V8i - msdefs.h file

#define     UNIT_SYSTEM_Undefined       0

#define     UNIT_SYSTEM_English         1

#define     UNIT_SYSTEM_Metric          2

#define     UNIT_SYSTEM_USSurvey        3   // based on US Survey Foot.

Connect - UnitDefinition.h

enum class UnitSystem

    {

    Undefined   = 0,

    English     = 1,

    Metric      = 2,

    USSurvey    = 3,

    };

Units.def file

#   Valid values for System are:

#   0 Undefined

#   1 US Survey Foot (English)

#   2 Metric

#   3 English (based on International Foot)

Thank you, Donna Rodrick