The Cabrillo Specification was originally developed by Trey Garlough, N5KO to provide a method for consistent data formatting that sponsors could use in the submission of contest logs. Contest sponsors including CQ, ARRL, and DARC quickly supported the idea. More importantly and key to its viability, leading program authors such as K1EA, N6TR, K8CC, W5XD, EI5DI and others also embraced the concept.

Since its earliest days, the Cabrillo Specification has been the recognized gold standard for contest logs and has revolutionized the contesting world. It has enabled many contests to support electronic log submission and automate the log checking process. The WWROF administers the Cabrillo Specification on behalf of the contesting community.

There are two versions of the Cabrillo Specification. V2 is now deprecated and should be supported only for legacy purposes. All users are urged to migrate to V3 as soon as possible. Cabrillo V3 is intended to be backwards compatible with previous versions of Cabrillo. Therefore if people submit logs that were created by Cabrillo v2-compliant loggers, their logs should be accepted by Cabrillo v3 email robots.

Questions about the Cabrillo Specification or enhancement requests should be sent to

Cabrillo Specification – Header

Cabrillo Specification – QSO Data

Cabrillo Specification Notes and FAQ

Change log