XSD No Data Tag, Self Closing, Empty?

I have seen a few answers to self closing tags in XSD, but non included empty definitions.

I have a large XML document that is automatically generated by a program.

The XML is similar to this:

<START>
<ON/>
<item1>
<item2>
<I data1="" data2="">
<I info1="" info2="">
</I>
</item2>
</item1>
</START>

For the tag named "ON", because it is self close and does not contain any data, how is this written in my XSD?

Any Feedback is much appreciated, Thanks