ANSI/ASQ Z1.4 (2008) is nearly identical to Mil-Std-105E. There are no changes in the tables of sampling plans. The only change in the switching rules is that ANSI Z1.4 makes the use of the limit numbers for switching to reduced optional. In addition, ANSI/ASQ-Z1.4 contains additional OC curves called scheme OC curves that describe the protection provided by the switching procedure during periods of constant quality. Numerous changes were also made to the explanatory text but which do not affect any procedures.