Swap test
The swap test evaluates a local page: replace the city name throughout the text — if the page remains true, it contains nothing genuinely local. It is the simplest doorway page detector that exists.
In practice
Our quality chain applies it automatically: every service-by-city page must contain elements that would fail the swap — real neighboring towns with distances, demographic data, territorial specifics. A page that survives the city swap goes back to content production, not to publication.