Semantic HTML tags don't exist. The HTML tags that are being passed off as semantic don't have any standard layout to make them useful in any way. Is there one

Semantic HTML tags don't exist. The HTML tags that are being passed off as semantic don't have any standard layout to make them useful in any way. Is there one <header> tag per page, or can each <section> have a <header>? If so, does the <header> go inside the <section> or before it, with some indication of which <header> corresponds to which <section>? What about <h1>/<h2>/etc. tags with regard to <section> tags? If you have a <nav>, does that go inside the <header>, or after it? What the heck is a <section> anyway? "Semantic" means that the tags have meaning, and the meaning of these supposedly-semantic tags isn't specified enough to provide any meaning.