Glossary
Redirect map
The spreadsheet that decides whether a migration keeps its traffic.
What it is
A redirect map lists every URL that exists today and the URL it will point to after a change, so each old address returns a 301 to its closest new equivalent instead of a 404.
Why it costs you money
It is the single artefact that separates a migration that keeps its search traffic from one that loses a quarter of revenue. Rankings are attached to URLs; when a URL disappears without a redirect, so does what it earned.
How to check it yourself
Export every indexed URL before anything changes, prioritise by clicks from Search Console, map each one explicitly, and verify on staging. Patterns and wildcards are where the misses hide.
Where this matters