Yes, you need to know what is is. I didn't but found the second last explanation here helpful: https://stackoverflow.com/questions/27434431/what-is-html-is-attr

Yes, you need to know what is is. I didn't but found the second last explanation here helpful: https://stackoverflow.com/questions/27434431/what-is-html-is-attribute https://stackoverflow.com/questions/27434431/what-is-html-is...