Function is_raw_text 

pub fn is_raw_text(name: &str) -> bool

The HTML RAW TEXT elements: their content is not markup, and escaping it CORRUPTS it.

★ A <style> HOLDING > IS A STYLESHEET THE BROWSER THROWS AWAY. HTML’s parser reads the content of <style> and <script> verbatim — character references are NOT decoded there — so a serializer that escapes text the way it escapes everything else turns the child combinator .list > li into .list > li, which is not a selector. The browser discards that rule and every declaration in it, silently: the page renders, the styling is simply absent, and nothing anywhere says why.

Same shape as is_void one function up — a rule HTML keys on the element NAME, which a serializer cannot infer from the content it is holding, held once so both renderers ask it.