When writing html code, you have to write doctype on the first line, and doctype is usually very long and people are too lazy to remember, so they basically copy what they have written before. But today I learned abbreviation of doctype. If your doctype is as follows:
<!doctype html public -//w3c//dtd html 4.01//en http://www.w3.org/tr/html4/strict.dtd>
You can use the following abbreviation instead:
<!doctype html>
It's simple and easy to remember, so you don't need to copy it in the future. btw, I want to learn from it and try it out. <!doctype xhtml> , but the result failed and the page became a mixed pattern. Any other tips you have. Welcome to provide them.