What is the Cabrillo format?

The Cabrillo format is a highly standardized, plain-text file format used globally by amateur radio contest sponsors. It was developed to provide a uniform way to structure header information (such as operator info, category, and claimed score) along with the actual QSO log data, allowing automated software to easily parse and score submissions. Distractors suggesting it is an over-the-air digital protocol or a method of exchanging information during a QSO are incorrect. Cabrillo is strictly a post-contest file format used for submitting your log, not a transmission mode or a set of operating rules. Because almost all modern contest logging software can automatically export a finished log in the Cabrillo format, it has become the universal standard for electronic contest log submissions.