@kovid
I haven't set any fonts - they are all on their default settings. The book text appears to be a Serif, the interface is Sans-Serif and the annotation window is Monospace, which seems to match the settings:
It would appear that if I change the monospace family to something like Arial, that the annotations are no longer in monospace. But it also appears that I need to change this for every book. Is there a setting elsewhere that allows me to set global font settings?
Still, this doesn't seem like a solution as it would also eliminate the opportunity to have monospaced font where a book calls for it. I hope you'll have some suggestions for how I can fix this or what could be changed within Calibre to do so.
Re: marker for highlights without annotations. I still disagree, but its obviously up to you, so I'll drop the issue. Thanks for the consideration.