There are two ways to give a feedback to who suggested an edit:
- you reject the edit using a custom reason
- you accept the edit as it is, and then you write a comment for that post @-referring the user who suggested the edit
In the first case, the message will be read from the user if the user looks at the page showing the suggestions he made, and clicks on the "suggested edit" link shown in that page.
It is probable a new user will not read that page, and check the feedback received for the suggested edits.
In the second case, the @-reference works for the users who edit a post. Keep in mind that the username is not auto-completed as when you reply to a comment given from a user for the same post, and you should use at least three characters from the username (excluding spaces and other characters).
Suggested edits are considered invalid also when a part of them is invalid, such as when the user keeps adding views to questions just because an answer is suggesting to use the Views module. In that case, you have two possibilities:
- you reject the edits, until the user is not anymore allowed to suggest edits for seven days
- you improve the suggested edit by removing the unwanted tag, or the part that keeps added to the posts
In the first case, the user could notice the suggested edits are not anymore possible, and ask a question on this very site; at that point, the user will get an explanation of why the suggested edits have been rejected, and learn what edits should be done.
If you see you keep improving edits from the same user to remove the same part added to the posts (e.g. a tag, a link, a phrase), and you tried to advice the user about what should be edited, then you could consider rejecting the suggested edits. If the user is not checking if the edits are welcome, you would keep improving edits until the user doesn't understand in which way the posts should be edited.