What are "SAI Keys", and what are the "Special Keys", the "CA Access Control Keys" and "CA Special Access Control Keys"?

The SAI Keys are configured on a single activator and then the control unit permits them to work on all the Activators/Transponder Readers in the system. The Special Keys only work on the Activators/Transponder Readers to which they are associated (even on multiple activators/readers). Each activator/reader can store up to 4 Special Keys, while the whole SAI system can be configured with a maximum of 24 SAI Keys. The"SAI Access Control Keys" and "CA Special Access Control Keys" are the equivalent of SAI Keys and Special Keys, with the difference being that they have been configured for Transponder Key Readers (part no. 14470/16470/20470).