You're reading the documentation for an older, but still supported version (GL013300).
For information on the latest version, please have a look at GL013301.

COORDINATE_SYSTEM

This is an enumeration type constant that means the coordinate system in the robot controller, and is defined as follows.

Rank	Constant Name	Description
0	COORDINATE_SYSTEM_BASE	Base coordinate
1	COORDINATE_SYSTEM_TOOL	Tool coordinate
2	COORDINATE_SYSTEM_WORLD	World coordinate
101	COORDINATE_SYSTEM_USER_MIN	User coordinate (101~200)
200	COORDINATE_SYSTEM_USER_MAX	User coordinate (101~200)

Defined in: DRFC.h

// reference coordinate enumerated value
typedef enum {
    COORDINATE_SYSTEM_BASE = 0,
    COORDINATE_SYSTEM_TOOL,
    COORDINATE_SYSTEM_WORLD,
    COORDINATE_SYSTEM_USER_MIN = 101,
    COORDINATE_SYSTEM_USER_MAX = 200,
} COORDINATE_SYSTEM;