This summary article presents an overview of the molecular relationships among the voltage-gated cyclic nucleotide-modulated channels and a standard nomenclature for them, which is derived from the IUPHAR Compendium of Voltage-Gated Ion Channels. The complete Compendium, including data tables for each member of the cyclic nucleotide-modulated channel family can be found at http://www.iuphar-db.org/iuphar-ic/.