Restrictions

Input key-A and input key-B cannot have different export control bits (CV bit 17 and 57); these bits must match. Use the Prohibit Export verb to change XPORT-OK to NO-XPORT (CV bit 17), or the Restrict Key Attribute verb to change T31XPTOK to NOT31XPT (CV bit 57). These two bits are propagated to the output key-token.