Algorithmic penalty
An algorithmic penalty occurs when an automatic filter demotes a site — for spam, links, or thin content — without notification. Diagnosis involves cross-referencing ranking drop dates with known algorithm deployment timelines.
In practice
The precise term would be 'devaluation': the algorithm stops counting what it previously counted. Recovery follows the engine’s schedule, not the site’s — fixing the issue is necessary but not sufficient; you must wait for the next filter pass, sometimes the next update. Logging SEO actions precisely makes correlation possible.