When data from external sources is fetched through a mapping whose lexical target path touches an Object-Fact Type marked with an elevated data sensitivity, the actual values must not be handed to external tools and callers (mainly the AI agent in the session).

Such values are now replaced with a stable pseudonym: a keyed hash whose key encodes the CaseTalk version and the day of use. This keeps equal values equal within a day - so lookups and joins keep working during a session - while preventing reversal of the original values and avoiding long-term correlation across days. Protected/Restricted values are hashed; Internal values are lightly redacted; Public/Unclassified pass through.

This is the data-hiding half of issue 0002735.