The Pinks series was the cross-reference file for subject correspondence generated by Senator Strom Thurmond's office for the period 1954-1976 before the introduction of the centralized Correspondence Management System by the Senate Computer Center in 1976. The original cross-reference files consisted of pink colored carbon paper copies-hence, the "Pinks" series.

The Subject Correspondence series is named for the central file used by Senator Strom Thurmond's office before changing over to a computerized filing system, the Correspondence Management Series (CMS), in 1976. Some subjects from the Subject Correspondence series for 1976 may overlap into the CMS series.