license is the PurchaseLicense the purchase was delivered under, or null
when none was recorded (every Store work, and brokered purchases made before licences
were recorded). null means "not recorded", never "no rights granted".
content.publication is the PurchasePublication a brokered work was published
under; null for a Store's work.
content.filing is the ContentSearchFiling for an SEC filing; null for every
other work, and for a filing bought before its filer was recorded.
A purchase record.
licenseis the PurchaseLicense the purchase was delivered under, ornullwhen none was recorded (every Store work, and brokered purchases made before licences were recorded).nullmeans "not recorded", never "no rights granted".content.publicationis the PurchasePublication a brokered work was published under;nullfor a Store's work.content.filingis the ContentSearchFiling for an SEC filing;nullfor every other work, and for a filing bought before its filer was recorded.