Originally processed as part of the former "Subject File" series, most of the material in this subseries was identified as a sampling of registrar correspondence that documented a specific function of that office--answering identification queries sent in from private collectors, other museums, and related businesses. These papers are processed here as General Correspondence. Correspondence between staff personnel and Kimball has been added and identified as Staff Correspondence. The "Administrative issues" series, "Personnel" subseries contains directives Kimball sent to multiple staff or all, including registrar personnel.

Throughout the approximately 20 years documented in this subseries, Jane Wolfe served as the Museum's registrar until her death in 1944. Other staff correspondents include the custodian Francis Richardson, assistant Elizabeth Abel, and two cataloguers, Elizabeth T. Woodring and Helen J. McClenahan. Gertrude Toomey, who appears on a few staff memos, began her long-term association with the museum as assistant registrar. The registrar also participated in WPA projects. In fact, Jane Wolfe's sister Beatrice came to PMA through programs provided by the WPA and in 1945 became the Museum's custodian. The "WPA and other relief programs" series contains that documentation.