Indentation doesn't work in the rich text editor

The rich text editor has "Indent" and "Outdent" icons - when you use them the preview reflects the change, but when you submit the change nothing is applied to the resulting page.

I also didn't find any documentation of a wiki markup for indentation, so either this is not supported by confluence and the icons should be removed from the richtext editor, or the markup is not documented and the editor is broken.

We would prefer if Confluence supported this feature, as indentation can be handy in certain situations.