It's not mandatory, and actually should be create error on anchor https://www.geeksforgeeks.org/how-to-specify-the-base-url-for-all-relative-urls-in-a-document-using-html5/
It's not mandatory, and actually should be create error on anchor https://www.geeksforgeeks.org/how-to-specify-the-base-url-for-all-relative-urls-in-a-document-using-html5/