Key to Commonly Abbreviated Spec. Information (all measurements are in inches)
CB = Center Back
Chest 1" down = means you measure the front of the garment 1" down from the armhole
1/2 = Measure only the front of the garment, then double that measurement to get the total circumference
Relaxed = Do not stretch the garment if it has elastic to measure, simply leave the elastic relaxed and measure
Stretched = Stretch the garment if it has elastic to measure, measure stretched