@exaltedwombat
Sigil does not offer a list of all code which it will be cleaned, when you affirm.
That's why I give up the wish to be asked before.
But I agree with you. It's better to be asked for all critical cleaning actions.
Ok, I give an example for the empty element. Please understand my reservation about that. I don't want to run into a new discussion of "what is good markup" again. Like in a thread some days ago.
In many books the editor/author uses a single empty paragraph to indicate a change of the perspective or the change of the time inside a chapter - where a split with a new chapter would be a to strong instrument.
For such a purpose
<div class="pause" />
it's nice markup.
A margin-bottom for the paragraph before or a margin-top for the paragraph behind is not appropriate.
The pause does not "belong" to only one these two paragraphs. But more important:
there's semantic in the message. Therefor CSS is not a good choice.