Every work has been assigned an RLCR number (Roy Lichtenstein Catalogue Raisonné number). The numbering follows the approximate chronological order of all works across all classifications. Preparatory works were placed before final works. Artworks with identical dates were numbered randomly within the year of their making.
When ongoing research requires a date change, a number may fall out of order. Newly added works receive a new RLCR number in ascending order, independent of their date.
The catalogue raisonné team has selected a group of primary alternate numbers to be listed in entries. These numbers stem from scholarly catalogues, relevant inventories or the RLF Archives. Not included are additional, often temporary numbers found on loan forms, gallery checklists, collector's inventory labels or other documentation. When pertinent, they are addressed in Remarks.
Numbers of drawings and prints in Bianchini 1970
Numbers of pre-Pop works in Busche 1988
Numbers of prints, posters and other editioned works in Corlett 2002
Numbers (preceded by "LC") for artworks inventoried or sold through Leo Castelli Gallery (Castelli Gallery as of 1999), expanded with letters indicating these classifications: "D" for drawing, "G" for tapestries. In rare cases two LC numbers are listed when the gallery erroneously assigned them to the same work.
Numbers of prints as assigned by the workshop
Numbers assigned to sculptures by the fabricator
NGA Gemini CR
Numbers of prints in the online catalogue raisonné of the works of Gemini G.E.L. published by the National Gallery of Art, Washington, D.C.
Numbers assigned to artworks by studio and RLF staff, starting c. 1990 when RL Studio Cards were created from existing artwork documentation. RL numbers were assigned as works were inventoried.
At times, RLF staff assigned additional RL numbers to artworks for organizational purposes. For example, sketchbook pages were renumbered to reflect their respective sketchbook and their order within it. In such cases, artwork entries carry two RL numbers, the more recent RL number and the older (formerly) RL number.
Abbreviation for "Slatkin." Numbers for tapestries in the inventory of the fabricator Union Commercial Corporation, Mirzapur, Uttar Pradesh, India. (This later became Adhiraj Exports.) The tapestries were initially ordered by Charles E. Slatkin Inc. Galleries, New York (in 1972 renamed Modern Master Tapestries, Inc.).
Numbers assigned to source material by RLF staff