Function fingerprint 

pub fn fingerprint(found: &[u8]) -> String

The one short name this city gives a secret it must refer to without holding: derived from the value, so one value reads alike in every session and two values never read alike in one.

A name counted out instead — cap-1, cap-2 — would give the same value a different name in every session and two different values the same name across two, which is how a stored credential comes back as somebody else’s.