This set me thinking about Michael Frayn's exploration of 'self'.
...he goes on to describe the marks and signs people used to identify themselves to others: authenticating seals, coats of arms, trademarks, insignia.
What's the role of information in authentication?
Authorities relied, then, primarily on words to identify people in official documents.
We can of course readily talk about the information content of words
Scars, birthmarks and moles become central to recognition
It is not too difficult to imagine working out the information needed to describe the presence of a scar, birthmark or mole.
Skin colour was also characterised
Again, we can easily come up with a value for the information needed to express skin colour.
...objects of identification issued by authorities for people to wear or carry
ID cards, which today would be digital documents.