Thanks for the downvote, but you're wrong.
> explicitly and implicitly describe the layout of an HTML document.
No, this doesn't happen.
> In fact, "HTML" itself is an acronym (HyperText Markup Language)
Duh.
> in which the "Markup" describes the function of HTML to "mark up" text in a similar way that editors once did in the print industry, describing which parts of the text should be bold, italicized, etc. or divided up and in what way.
Which has fuck-all to do with the layout.
I didn't downvote you, and I'm not wrong. And all you're responding with is invective. Go touch grass and read a book. Bye.