Lists that survive contact with a mail server.

The brief sets the boundaries; everything downstream inherits them. Fields are filled only where a source supports them. Nothing in the file is there to reach a total.

Address normalisation

Standardising location data before comparison, so one place does not read as several.

Legal-entity grouping

Deciding whether branches roll up to one parent or stand alone, and applying it consistently.

Definition work

Turning a loose brief into something precise enough to count the same way twice.

Questions about where this comes from are expected and answered.