The structured voice the engine drafts in: tone, characteristic phrases, vocabulary, sentence style and what it avoids, capped exactly as the drafting context caps them. `register` names which voice this is and the registers do not sound alike: 'brand' is the voice of the product's own website, 'personal' is the founder's own extracted from writing samples they supplied, 'imported' came from an imported brief, and null is a producer that has not been classified. `source` is the same fact in the older producer vocabulary ('site', 'uploaded_samples', 'imported'). Pass ?register= to ask for one register rather than the current row; has_profile is false, with a null profile, when that voice has not been extracted yet.