| name | okhp3-mermaid-data |
| description | Data model and relationship diagrams in Mermaid — entity-relationship (ER) diagrams, class diagrams, schema documentation. Use when the user wants to diagram a database schema, data model, object structure, class hierarchy, or entity relationships with cardinality. Always load okhp3-mermaid-core first for audience/type/theming. |
OKHP3 Mermaid Data
Data modeling vocabulary, loaded after okhp3-mermaid-core.
ER Diagrams
Entity-relationship modeling with cardinality notation. See references/erd-syntax.md for entity/attribute syntax and cardinality conventions (one-to-one, one-to-many, many-to-many — exact notation and when PK/FK annotations are included vs. omitted for Executive/Analyst audiences).
Class Diagrams
Object structure, relationships, methods. See references/class-diagram-syntax.md.
Schema Documentation Patterns
When a diagram is documenting an existing schema (vs. designing a new one), see references/schema-documentation-patterns.md for how much of the real schema to surface at each audience tier — Technical gets full field lists and types, Analyst gets entity names and relationships only, Executive rarely needs this diagram type at all (flag if an Executive-tier ER diagram is requested; it may be the wrong type per core's type matrix).
Cardinality Conventions
Consistent notation across all OKHP3 ER diagrams — defined once in references/erd-syntax.md, referenced rather than re-decided per diagram.
