<textarea> elements do not contain a label.

For example. in https://download.java.net/java/early_access/javafx26/docs/api/javafx.graphics/javafx/scene/doc-files/cssref.html in the "@font-face" subsection:

<textarea rows="8" cols="132">
     @font-face {
        font-family: 'sample';
        font-style: normal;
        font-weight: normal;
        src: local('sample'), url('http://font.samples/resources/sample.ttf&#39;;) format('truetype');
    }
</textarea>

Either add a <label> element:

<label for="font-face-rule">@font-face Rule</label>
<textarea id=font-face-rule rows="8" cols="132">
...

Or change <textarea> to <pre>

See 2.4.6 Headings and Labels in OAG 3.2.