This question was posted in response to the following article: http://help.adobe.com/en_US/digitalpubsuite/using/WS67cb9e293e2f1f60-12e05bfc12f6c86d767-7 fff.html
If Description is for internal use only why this field is required and not the optional? It's not clear why do this field even was introduced. Also please add this line to the description for the "Folio Number": Publication Name and Folio Number appear in the viewer navigation bar as a folio title concatenated in one line with the Publication Name in all caps.
Also it would be good to have additional info on each field: field purpose, where it is used, could it be changed and what are consequences.