Captured, and stamped

Files nobody can regenerate here, like a render or a copy from elsewhere. Each is stamped with what it was made from, so the gate knows when it is out of date.

Written, not built, with a reason

Everything else is written - by a person, or by an agent - and never built: nothing regenerates it, so it is current only while someone keeps it so. Every rule that says so carries its reason.

Drift

A value said by hand in two or more files that no source holds: a copy nobody is keeping current. Each is drawn beside the files that say it, and wherefore check drift holds the count to what the corpus allows, so it is seen, and seen shrinking.