- The units of meaning is not the "line", but the word, sentence, paragraph, section.
- Editing a word/sentence/paragraph/section is different than moving it elsewhere.
- If a sentence or paragraph or section changed, you would want to show which specific parts of it changed, instead of highlighting the entire larger unit.
- It would likely be helpful to show the change in context, possibly as a before/after toggle.
- Markup would be very difficult to parse. (Open/close tags across sentences, etc.) But markdown would be all right.
- There are trivial changes, meaningful changes, and then meaningful changes that you want to call out.
- Adding line breaks don’t matter, unless it forms a new paragraph.
Guidelines Behind Prose Diffs