I1S1O1G2R1I1V4
11 points
ISOGRIV is validvalid
a line drawn on a map such that all points have equal grid variation [n ISOGRIVS]
a map line indicating equal grid variation [n -S]
a line drawn on a map such that all points have equal grid variation [n ISOGRIVS]
a map line indicating equal grid variation [n -S]