Very often, an edit will be entered that is slightly wrong (e.g. a release with a typo in the tracklist) or not as specific as it could be (e.g. a "performed" AR rather than a "performed vocal"). In this situation, there are two option:

A) Submit a new edit that corrects the actions of the original edit.
B) Cancel the original edit and submit a new edit that acts correctly.

Both of these have drawbacks. A is usually easier for the editor, often saving them from retyping lots of data, but still requires them to link from the original edit to the new edit, and ideally provide a summary before that link of the changes made. This situation of awkward for voters, as they need to review and vote on two edits as a pair, and have to follow a link from one edit to the other rather than being able to scan down a list of edits, each of which is complete in isolation.

B is usually better for the voters. New voters will only see one edit, and can vote accordingly. Additionally, if the editor adds a link from the cancelled edit to the new edit, then anyone who commented or voted on that edit will be notified, and will received a link to the new edit so that they can vote again. This does however require the editor to retype (possible a lot of) information, and to link from the cancelled edit to the new one. They therefore often end up choosing A, and not necessarily adding forward or backwards links or explanatory comments.

A preferable scenario would be such that an editor can modify an edit that they've made. In itself, modifying an edit would probably be very complex. It would likely required a new user interface, and to avoid 'editing by the back door' all votes up to the point of modifying the edit would need to be ignored, and the expiry time would need to be extended to 14 days again.

However, exactly the same effect could be achieved by adding a little user interface to simplify option B above. I'd suggest that, when viewing an edit of their own, an editor has a link titled "modify edit" (or similar available to them). Selecting this would take them to the same interface as was used to created the edit in the first place, but pre-populated with the data that they had previously entered. They could then modify this data to suit, before clicking either "Cancel" or "Modify Edit" (as opposed to "Enter Edit"). Selecting "Cancel" would do as expected, and the original edit would be left untouched. Selecting "Modify Edit" would do several things (ideally atomically):

1) Create a new edit that acts exactly ad if the user had entered this edit normally.
2) Add a comment to this edit, saying, e.g. "modification of edit #

".
3) Cancel the original edit.
4) Add a comment to the original edit, saying, e.g. "modified as edit #

".
5) Notify users who'd voted or commented on the original edit, exactly as they'd be notified as a result of any other comment.

I think that the above proposal would solve an awkward problem, especially noticed by novice editors who often submit partially correct edits, and who will find it awkward and offputting cancel and resubmit their edits correctly, especially if several iterations are required.