This read-write octet string (0-8 bytes) stores up to eight non-critical POST error codes for use by diagnostic utilities such as Quicktest and CIM, and only a zero-length set to clear it will succeed, with all other write attempts failing. An admin or diagnostic utility clears this buffer via a zero-length set after those non-critical POST codes have been reviewed, resetting it for the next boot cycle. Attempting to write a non-empty value here to add a new code would fail, since only clearing is a permitted write operation.