Google has 12 bots crawling the web and the apps. The crawlers are APIs-Google, AdSense, AdsBot Mobile Web Android, AdsBot Mobile Web, AdsBot, Googlebot Images, Googlebot News, Googlebot Video, Googlebot (Desktop), Googlebot (Smartphone), Mobile AdSense, Mobile Apps Android.
With these bots, Google crawls the content of each website, and since 2017 Google is also crawling the ads.txt files to verify the authorized advertising sellers.
Google labels each URL with Digital content labels and Sensitive topic classifiers. This technology is then available in Campaign Manager (CM), Display & Video 360 (DV360) and Google Ads. Google says the classification process looks at hundreds of aspects of a site’s content.
Advertisers can whitelist or blacklist these content labels.
Google Digital Content Labels
DLG: Content suitable for general audiences
DLY: Content suitable for families
DLPG: Content suitable for most audiences with parental guidance
DLT: Content suitable for teen and older audiences
DLMA: Content suitable only for mature audiences
DLNR: Content that has not been labeled
Google Ads Sensitive Topic Classifiers
Tragedy and conflict
Sensitive social issues
Sensational and Shocking
Profanity and rough language
Sexually suggestive
Parked domains
Ingame
Live streaming video
Invideo
In Google Ads, the Sensitive Topic Classifiers are only available for pre-bid blocking (exclusion/negative targeting).
On DV360, advertisers can use Sensitive Topic Classifiers for reporting and prebid blocking.
YouTube Content Exclusions
In YouTube TrueView campaigns Google has several extra brand safety content classifiers:
Tragedy and conflict: Obituaries, bereavement services, violence, war, missing persons, and more
Profanity and rough language (beta): Moderate or heavy use of profane language and curse words
Sexually suggestive content (beta): Provocative pictures, text, and more
Sensational and shocking (beta): Content that creates shock value, including sensational, gross, and crude content
Embedded YouTube videos
Live-streaming videos
YouTube videos that appear in online or mobile app games
Other ways to protect the brand
Besides the above brand safety measurements, advertisers are able to protect their brand by excluding keywords, URLs, Apps, Topics (categories of content), and languages.