How do edits work?
Users can edit the questions and answers submitted to the site. This gives the site a wiki feel, and allows the information to constantly evolve and remain up to date. Those users who are allowed to edit a post can do so by clicking the edit link associated with that post.
Multiple edits made by the same person may be combined into a single revision, if they occur within a short period of time (currently 5 minutes). Edits made by the original author are considered part of the base revision if submitted within 5 minutes of posting (unless someone else submits an edit first, or posts a comment below).
It is possible to “roll back” changes made in a revision. This can be done during editing by selecting a previous revision to edit from the dropdown, but can also be accomplished via the "rollback" link displayed on previous revisions within the revision history list - the latter is a little more convenient, and will earn you a bronze "Cleanup" badge when first used.
When multiple editors submit changes, the last one in “wins”, regardless of who began editing first. Both revisions are preserved however, and changes lost can be restored either by rolling back to the previous revision or by manually copying text into a new revision.
To promote good edits, a user who suggests an edit to someone else’s post will get +2 reputation points when that edit suggestion is approved. You do not get the reputation bonus if the edit is automatically approved, whether this is because you are editing your own post, you are editing a community wiki post, or you have at least 2000 reputation and all of your edits are auto-approved. Also, you are limited to a maximum of 1000 reputation points earned from edits.
Who may edit a question or answer?
The original author of a question or answer may edit their own post. Additionally, users with a certain level of reputation may edit any question or answer. The one exception is locked questions, which may not be edited by anyone, including the original author, until they are unlocked. Additionally, the amount of reputation needed to edit community wiki posts is much lower than that needed to edit ordinary questions and answers. If a user does not have enough reputation to edit directly, they can still suggest an edit (see a related FAQ question, How do suggested edits work?).
How can you tell what has been changed between edits?
Once your question has been edited, there will be a note of it, with the time since the last edit hyperlinked to a revision history for the post.
Each revision is displayed in a separate, collapsible section. Older revisions start out already collapsed. If a comment was specified by the person editing, that will be displayed in yellow next to the revision number; otherwise, the total number of characters added or removed in that revision will be listed, as well as whether the title and tags have been changed (questions only). Once expanded, the revision will be displayed, with changes highlighted.
The edit link on older revisions lets you copy that edition to a new revision, essentially letting you roll back to that revision and edit it at the same time.
Revision diff color key:
- Green background: characters added
- Red text +
strikeout: characters removed
In order to prevent a series of tiny edits from showing up in the revision history, a single user who edits a post is given a 5-minute grace period, except under one of the following conditions:
- The previous revision was a rollback.
- The new revision is a rollback.
During this period, any additional edits they make are collapsed into the same edit in the revision history, displaying only the final outcome of all their edits within that 5 minute period. The grace period ends after exactly 5 minutes, or if:
- Another user edits the post, at which time their grace period begins.
- A comment has been added to the post since the previous revision by anyone other than the editor (ignores deleted comments).
- If the post being edited is a question and an answer has been added since the previous revision (ignores deleted answers).
- The question has been closed since the previous revision.