The request for often refers to specific historical or cataloged images, most notably plate 303 from Eadweard Muybridge's Animal Locomotion series.
Depending on the context, the "303" designation typically refers to one of the following:
: Scanned pages from legal records, such as page 303 of the General and Special Laws of the State of Texas , often archived through the Digital Public Library of America.
: This is the most common historical reference for "(303).jpg." It depicts a nude woman picking up a ball and throwing it as part of Muybridge’s 19th-century photographic motion studies.
: An Attic black-figure column krater in the Getty Museum's collection (item 96.AE.303), which shows a scene from the Odyssey where Odysseus escapes the Cyclops.
: A photo of the Palais de Chaillot in Paris, sometimes labeled with this number in image sharing batches.