You would need to add child nodes inside the style node in order for them to appear in the RT Editor.
You would need to declare a value and then a CSS name on which styling can be applied
Something like this:
<styles jcr:primaryType="nt:unstructured" features="*"> <styles jcr:primaryType="nt:unstructured"> <sampleStyle jcr:primaryType="nt:unstructured" cssName="sample" text="sample description"/> </styles> </styles>
even without adding child nodes inside the style node we should still be able to see the "S" symbol right, with blank dropdown like in the screenshot below, which is not appearing in my case