SEO tool maker Ahrefs said Thursday that it’s “cleaning up any past results that may have been affected” by what it calls the “poisoning” of search results by Google, in which suspected SERP data providers are shown different results. Its post doesn’t say which dates, reports or metrics the cleanup covers.

Agency SEO platform SEOmonitor says in its help center that between Oct. 9 and 13, “some of the incorrect results were recorded in the platform” and that the affected keywords were reprocessed on Oct. 13, the day it put a new check in place.

Three other companies ( AccuRanker , BrightLocal and SerpApi ) have also described how each of them treats these results. These descriptions are side-by-side so you can see how each company describes the steps taken for an individual rank before storing that data, when displaying it to users and after recording it.…