Main Classification File

USPTO patents in the Dataverse databases had US Patent Classifications (USPCs), while EPO and PCT had International Patent Classifications (IPCs) and Cooperative Patent Classifications (CPCs). The concordance between the two classification systems is provided in another file. 3 columns, 79.6M lines, "|" delimited; the columns are:--Pub_number: the patent publication number.--class: the patent classification number.--class_type: the type of classification this represents. "u" indicates USPC, "i" indicates IPC, "c" indicates CPC, "m" indicates an inferred IPC from the USPC-to-IPC concordance (described below), and "w" indicates the WIPO field.