This read-only octet string (0-2 bytes) is the data destination register value pinpointing which memory bank had the correctable error, with its interpretation dependent on the specific machine type. An admin, typically with vendor documentation for that server model, decodes this to physically locate the failing bank rather than only knowing that some memory error occurred. Combined with cpqHeCorrMemErrHwLocation, this narrows a fault down to a specific bank on that particular chassis.