How agents, skills, and commands work in Claude Code projects.
GitHub conventions -- branch naming, commit format, issue/PR templates, and safe issue/PR referencing in comments.
API error response format -- machine-readable codes, human-readable reasons, status code rules.
Language-agnostic code hygiene -- honest comments, no dead/reinvented/duplicated code, truthful names, real implementations, and scoped (never blanket) diagnostic suppressions.
Language-agnostic structural craft -- decompose on responsibility not size, prefer deep modules over shallow piles, and shape cohesion, coupling, interfaces, error contracts, and data invariants. Sibling to code-hygiene and readable-code.
Documentation writing conventions -- style, structure, tone, and quality standards.
CSS design system principles -- token usage, semantic layering, mobile-first, component isolation.
Logging conventions -- level usage, formatting style, structured output.