rule · _guidelines/spec/1.27 · s-ce9wbaut6edfuy8
An entity is declared once
Checkedconfirmed by its owner
Every entity of the system — what a term names, such as a user or a session — is declared once: by the term that names it, in contracts (§s-7vm323mhry2enx3), and its data, where the specification describes them, by one data record node, standing in the domain that provides it or, where no single domain does, in contracts. No two data record nodes share a name.
Why
Two definitions of one entity are two owners of it, and two owners change it apart; the duplicate is usually the first visible trace of one domain doing another's work.