This document defines an architecture extension for physical location codes. One use of location codes is to append failing location information to error logs returned by the event-scan and check-exception RTAS services. Refer to for more information on the format and use of location codes. For event logs with Version 6 or later, the location code of FRU call out is contained in the Primary SRC section, FRU call out sub-section of the Platform Event Log format.