The Ridorian were a species that had contact with the Ferengi and the Klingons before the Ferengi purchased warp drive from the Breen. (New Worlds, New Civilizations short story: "A Dry Day on Ferenginar")

Whenever a group of Ridorians are walking together, their customs state that they must arrange themselves in column rows according to their height. In 2372, a group of Ridorians started a fight on Deep Space 9 when two disagreed on who was taller. (DS9 novel: Trial by Error)