Whatever we choose as type policy for our properties will nevertheless pertain to a record that can’t divert from its unicity-based type policy. For there are functional reasons (e.g. the ability to create subdbs) that involve to consider records this way. Thus the type policy relies on a unique principle only when this principle is unicity.
However, it is as difficult in the unicity perspective on things as in the extrinsic-intrinsic perspective we borrowed from Jean-Claude Gardin, to designate a property or an object that matches absolutely the chosen basic dichotomy. This fact shouldn’t be ignored if there’s any meaning to grasp from the word knowledge.