You can make up HTML tags, https://maurycyz.com/misc/make-up-tags/.
So, yes, it’s a bit unknown but it’s totally correct to have HTML elements like `<foo-bar>`. The hyphens declares an _unknown custom element_ (which becomes known once defined with JavaScript), and is perfectly valid. You can style it, like any other element.
Too bad the examples in the article are not great: semantically correct elements exist such as `article`, `blockquote` etc.
@hywan I'll note: The only reason browsers ask you to include the hyphen is for forward-compatibility. They might want to define new elements (without hyphens) in the future, at which point pages which uses them for something else *might* break.
Still... It'd work for now even if you exclude hyphens!
@alcinnz Yes and no. An unknown tag without a hyphen is an… unknown element, which is an error. However, an unknown custom element _is_ a valid element 😁.
