There are five things to be de-indexed by Google,
1. Concealment
2. Spam
Content and automatically generated links
Hidden links
Scraped content
Creation of malicious web pages
Dumping content
3. Keyword stuffing
4. Duplicate content
5. Unnatural inbound links to your website
Therefore, make sure that the website works correctly without errors, duplicate content, unnatural links, blacklists or malicious lists, and check your website today to get a Google fine.