[[Knowledge]] that cannot be fully articulated — it exists as judgment, intuition, [[Pattern recognition|pattern recognition]], and [[Expertise|expertise]] acquired through experience. Also called **know-who** or **expertise knowledge**.
^definition
Examples:
- knowing which engineer to call for a database incident
- recognising a bad architectural decision from experience before it ships
- a senior consultant's instinct about what a client really wants
^examples
## In [[Knowledge base design]]
Tacit knowledge mostly lives in people and resists capture. What can be partially externalised:
- [[Decision log|Decision logs]] and [[Post-mortem|post-mortems]] — the *why* behind choices
- Q&A transcripts and forum threads — expertise externalised through questions
- Mentorship notes and failure stories — patterns experienced people recognise immediately
A [[Knowledge base|knowledge base]] that only stores factual and procedural content will fail agents that need this context.
^kb-implications