ONIX display - other values - Unknown accessibility - code 08

[chrisONIX]

In the Display techniques for ONIX document - propose to add the Unknown accessibility (ONIX code 08 from list 196) to the Conformance section.

If we add this we can advise about checking the ONIX for this ISBN periodically to see if this has been updated. 08 is used when information is not yet available aor an accessibility audit is being carried out.