Occasionally, the page count data provided by publishers who are still sending data in ONIX 2.1 is not translating successfully into the ONIX 3.0 extent information.

In these cases, this means that the page count is not present on the new display (based on ONIX 3.0) whereas it was on the legacy display (based on ONIX 2.1).

This has no effect on the normal display of page counts provided in ONIX 3.0