Change bars can represent different kinds of changes: Additions, removals, style changes, numbering etc. Some of these have their own visual indications, e.g. the added or removed characters; and some - do not, and are only indicated by the presence of the change bar. It is difficult/impossible to realize what exactly the change is, when the change bar is the only indication. For that reason, I suggest that when the mouse is hovered over the change bar, we get a pop-up, with a textual indication of the change. It should read somewhat like, or exactly like, the text summarizing the difference between a style and its underlying style, in dialogs like Paragraph Style (under Organizer | Contains).
Please add a screenshot for the "change bar".
Created attachment 189352 [details] screenshot of change bar Well, here it is, but - as I was making this screenshot, I realized that we don't actually get change bars unless at least some characters get visually marked as changes. So my suggestion is invalid.
Heiko, please have a look at bug 157099. If that were resolved, this bug would become valid :-)
Heiko, please have a look at bug 157098. If that were resolved, this bug would become valid :-)