AGS – SEO WIKI
AGS is a Yandex filter that determines the quality, usefulness and interest of sites for users.
Based on certain algorithms, the sites being checked may be excluded from ranking or not indexed at all.
There are 2 types of AGS filters known: AGS-17 and its improved version AGS-30. Both filters are based on Yandex search engine rules that every webmaster must adhere to when creating sites: pages must have unique content, be filled with useful information for the user, not contain spam, etc.