Google AdSense - How to Block / Allow Ad
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Go to Google AdSense website . In the Allow & block ads tab, under Blocking options, you can go to General categories and Sensitive categories. Just click on the Allowed or blocked column to allow or block a particular ad category.
Here, in the General categories, I blocked the category Gambling.
Likewise, in the Sensitive categories, I blocked the category References to *** & *********.