The `<dd>` element can contain non-Phrasing [Flow content](https://html.spec.whatwg.org/multipage/grouping-content.html#the-dd-element) ("block" elements, in HTML4 terms) and can itself appear only in the same places where its `<dt>` counterpart can appear. So the definitions of these elements should probably be treated the same way, and the `<dd>` clearly can't be considered "inline" element

The `<select>` element is categorized as "[Phrasing content](https://html.spec.whatwg.org/multipage/form-elements.html#the-select-element)" (correponding to "Inline" elements in HTML4 terms) and doesn't break a line of text (exactly like, e.g., `<input type="text">`), so it should be categorized the same way.

The `<ruby>` element is part of "Text level semantics" section of the spec and is categorized as "[Phrasing content](https://html.spec.whatwg.org/multipage/text-level-semantics.html#the-ruby-element)" (corresponding to "Inline elements" in HTML4 terms). It doesn't break lines as "block elements" do.