Verbal identity
The words half of a brand: the name, the tagline, the vocabulary you own, and the rules for how everything you write sounds.
See it
What it is
The language half of a brand, built to sit alongside the visuals. It covers naming (company, products, features, plans), the tagline, voice principles, a lexicon of words you own and words you never use, mechanics conventions (sentence case or title case, Oxford comma, how you write numbers and dates), and a message hierarchy saying what gets claimed first. Mailchimp's public content style guide and Innocent Drinks are the usual reference points.
Reach for it when more than about three people write customer-facing text, when the homepage and the error messages sound like different companies, or when you need to brief an AI tool and 'friendly but professional' keeps producing mush.
Gotcha: three adjectives are not a verbal identity. 'Bold, human, clear' is unusable until you show before-and-after rewrites and a word list with real substitutions. Second gotcha: voice is constant, tone moves with context. Guidelines that skip that distinction produce a playful joke in the failed-payment screen, which is where brand personality goes to die.
Ask AI for it
Write a verbal identity guide using [POSITIONING], [AUDIENCE], [VOICE TRAITS WITH THEIR OPPOSITES], [APPROVED SAMPLE COPY], and [MESSAGES THAT MUST COME FIRST]. Derive every rule and rewrite pair from those inputs, and preserve the recognizable language already in the samples. Include: three voice principles, each with a one-line rule plus a 'we say this, not that' rewrite pair; a tone matrix covering four contexts (onboarding, marketing page, error state, apology or outage); a lexicon of 10 words we use and 10 we avoid with reasons; naming conventions for products, features, and plans; and mechanics rules (capitalization, punctuation, numbers, contractions). Keep every rule demonstrated with real sentences, not adjectives, and flag any naming or terminology decision the supplied inputs do not support.