Where is the doc for modifiers?

How to?
#1

I saw that there are some sort of modifiers, such as div#divID:contains("a given word")

I look through the site and can't find those modifiers, does anyone knows where are those located?

Thanks!

#2

Ya, those are CSS selectors, and they are not specific to Web Scraper. Many other programs and programming languages use them. These are the links I always refer to:

https://www.w3schools.com/cssref/css_selectors.asp
https://api.jquery.com/category/selectors/
http://nthmaster.com/