In the “Search Policy Documents” search mode, there are numerous filters available to help users structure and/or limit a search query. Filters are located on the left side of the page.
Each filter has an option in the bottom left corner called “show more.” Clicking on this link will display the filter in full.
Index of policy document filters
Note, that while all Overton’s policy documents have been assigned a policy source type, not all have been assigned a corresponding source subtype
Use this filter to see the policy sources in your results set and/or filter your search query to see documents from a specific policy source
Sometimes this metadata is to help distinguish groups of documents from a source (i.e., “117th Congress” or the “Scottish Affairs Committee”).