IBM Carbon's content guidelines are part of the open-source Carbon Design System: practical writing standards developed from real IBM product interfaces, covering brand voice, sentence-length rules (typically ≤25 words), plain language, and detailed accessibility guidance.
Free: part of the open-source Carbon Design System.
Content designers wanting a practical, real-world enterprise content style guide with concrete accessibility-focused writing rules, not merely abstract principles.
The accessibility section (linking to IBM's Accessibility site and WCAG guidance) is particularly strong, worth referencing specifically when auditing UI copy for accessibility compliance.
IBM Carbon's open-source content guidelines for consistent products.
