Applicable version: this documentation is based on PlantUML 1.2025.3 (June 2025), which introduces new syntaxes (notably CSS-style styling) and removes some legacy commands.
PlantUML is a text‑based language for creating both UML and non‑UML diagrams. Every diagram starts with @start… and ends with @end…. The type of diagram is defined in the start tag (uml, mindmap, nwdiag, etc.). Comments are written with // or /'…'/. The title, header, footer, legend and caption directives are common to all diagrams and add contextual information.