Hello,

I am seeking assistance to obtain USPC classification data for patent applications filed during 2008-2014 in the Patent Examination Research Dataset. While using PatentsView, I encountered a few challenges::

1. I'm looking for a harmonized USPC classification for all patent applications in my sampling period (2008-2014). In the Data Downloads section, only pg_uspc_at_issue.tsv.zip is available. There's no pg_uspc_current. Is there a way to get a consistent classification scheme over a decade, considering classification revisions?

2. Using PatentsView API, I retrieved USPC information for granted patents. Could you confirm if uspc_mainclass_id and uspc_mainclass_title reflect the current classification scheme? Also, how can I identify the primary class when multiple USPC codes are assigned to a patent? Google Patents Public Data on BigQuery reports the static "at-issue" uspc from the published patent document, distinguishing the primary/first code from others. Is there a similar feature in PatentsView?

3. I found uspc_current_201908 and mainclass_current tables on Bigquery under patents-public-data.patentsview dataset, which seems like historical data production by PatentsView. Do these represent the current uspc (as of 2019.8) for all patents? And does this data align with the USPC information provided by the PatentsView API?

Thanks in advance for your help, and for making PatentsView such a valuable resource for patent research!

Best,
Kate