Adopt arc42 + C4 for site structure
Context
We need a documentation structure for the Cognitive Exoskeleton. Considered three approaches: C4 Model (hierarchical zoom — System Context → Containers → Components → Code; great for navigation but only a diagram framework, not a full doc structure), arc42 (12-section architecture template, industry standard), and a custom structure (flexible but risks reinventing the wheel and needing later restructuring).
Decision
Use arc42 as the content structure and C4's progressive zoom for the Building Block View. arc42 gives a proven, standards-based skeleton; C4 gives drill-down navigation inside the biggest section (Building Blocks). We adapt arc42 — keeping sections that add value and skipping the enterprise-heavy ones (§2 Constraints, §10 Quality Requirements, §11 Risks & Tech Debt, §12 Glossary).
Consequences
Each page maps to an arc42 section (see Methodology → arc42 Semantics). New content needs to find its arc42 home before being added. The framework guides; it doesn't constrain — skipped sections can be added back if the system grows to need them.
References