Government-published documents often fail to communicate clearly—not only with citizens but also with professional readers such as civil servants. Visual or multimodal approaches remain rare. This is a particularly unhelpful practice in regard to legal–bureaucratic instructions (e.g., contracts, rules, policies), which exist to guide compliant behavior. This study explores the development and experimental evaluation of a diagrammatic guide of terms and conditions for public procurement that is addressed to civil servants. Results show that the diagrammatic format, compared to prose, significantly enhances comprehension accuracy and answering speed and is perceived as more appealing and functional by users.