[These lines are filters. They are the rules by which the ad blocker (in this case u block) selects specific web content to remove when matches are found. Apparently they can also find JavaScript content which is what they seem to do: removing the JavaScript parts of YouTube.com that show the ads]
" If you're a ublock origin user, copy this line and paste it through My Filters tab. Enjoy!
youtube.com##+js(set, yt.config_.openPopupConfig.supportedPopups.adBlockMessageViewModel, false)youtube.com##+ "
[These lines are filters. They are the rules by which the ad blocker (in this case u block) selects specific web content to remove when matches are found. Apparently they can also find JavaScript content which is what they seem to do: removing the JavaScript parts of YouTube.com that show the ads]