Explicit preferences the user has stated. Structured YAML with categories: communication (response length, formality defaults), scheduling (preferred meeting times, buffer preferences), content (formatting preferences, tone for different contexts), and tool-specific preferences. WRITE when user explicitly states a preference ("I prefer...", "Always...", "Never..."). UPDATE when user changes a stated preference. Each entry includes: preference, context, and when it was stated. Higher confidence than learned preferences—user explicitly said this.