When crawling a webpage, if a custom selector is selected, but the initial page does not have a suitable selection object, it will cause the crawler to fail. If a custom selector is not used, the truly valuable page (which can filter out a lot of useless information through the selector) will have a lot more useless information, such as the "homepage". So this submission can be used when a custom selector is available, and when it is not possible, use "body" as the CSS selector.
When crawling a webpage, if a custom selector is selected, but the initial page does not have a suitable selection object, it will cause the crawler to fail. If a custom selector is not used, the truly valuable page (which can filter out a lot of useless information through the selector) will have a lot more useless information, such as the "homepage". So this submission can be used when a custom selector is available, and when it is not possible, use "body" as the CSS selector.