Here is how we measure:
SS = Shoulder to Shoulder, measured from arm seam to arm seam, at the top of the shoulder
NW = Nape to Waist, measured from bottom of collar to level of arrows in back
NK = Nape to Knee, measured from bottom of collar to bottom of coat
SW = Shoulder to Wrist, measured from arm seam at top to end of sleeve
C = Chest, measured around the bust -- largest chest measurement
W = Waist, measured near navel
IS = Inseam, measured from crotch to end of jod leg (when measuring yourself, go to floor in bare feet, we will add 4 to 6")