The Köchel-Verzeichnis is abbreviated “K.” or “KV.” while the Kirchmeyer catalog is abbreviated with “K” or “KV”. There are other K catalogs for other composers such as Köchel’s catalog for Wolfgang Amadeus Mozart, or Kirkpatrick’s catalog for Domenico Scarlatti or the Krebs catalog for Carl Ditters von Dittersdorf or even Köchel’s catalog for Johann Joseph Fux. Usually, the context of the composer prevents catalogs from being mixed up. However, in order to make sure to cite a catalog without ambiguity, always check the RAK (RAD, respectively) standard first.
... see a comprehensive list of catalogs