A Notice of Variation, or NoV, is a document issued by Ofcom which varies your amateur radio licence.

In the context of packet radio, an NoV can be issued against your personal amateur radio licence to allow explicitly for the types of operation often desired by permanently running packet node owners, as well as the issuance of a non-personal GB7xxx or MB7Nxx callsign of your choice.

An NoV can be applied for from the ETCC, a subcommittee of the RSGB, who offer a “triage” service to Ofcom. See the Guide to Repeater and Internet Gateway Licensing, section 3.