marko/test/test-project/xml-templates/entities.marko.xml

<c-template
    params="">
    <div data-attr="Hello &lt;John&gt; &lt;hello&gt;">
        <attr name="data-nested-attr">Hello &lt;John&gt; <![CDATA[<hello>]]></attr>
        <attr name="data-nested-attr2" value="Hello &lt;John&gt; &lt;hello&gt;"/>
        Hello &lt;John&gt;© <![CDATA[<hello>]]>
        ${startTag:START}
    </div>
</c-template>