The COMPUTATIONAL or COMP phrase is specified for internal decimal items. Such an item appears in storage as 2 digits per byte, with the sign contained in the 4 rightmost bits of the rightmost byte. An internal decimal item can contain any of the digits 0 through 9 plus a sign. If the PICTURE of an internal decimal item does not contain an S, the sign position is occupied by a bit configuration that is interpreted as positive. Of all USAGEs, USAGE COMP is the most efficient in terms of operational performance.