A stealth edit occurs when an online resource is changed without any record of the change being preserved. The term has a negative connotation since it is a technique which allows an author to attempt to retroactively change what he or she said.
A common scenario would be a reporter posting a diatribe against something, followed by a blogger posting that the reporter is too extreme, followed by the reporter stealth editing the original post to be less extreme. The result is that the blogger looks like the one who is too extreme since the public can't tell that the original post has been changed.
A variety of non-stealthy techniques exist when making corrections or updates:
- The title of the page can have an update notification prepended or appended to it, along with a brief description of what has changed.
- Deletions may remain but be crossed out, while additions are made in a different colour. 
- Publicly accessible change logs may be kept for every edit. 
The common feature is that all these methods explicitly let the reader know that an edit has been made.
A grey area exists when the edit is trivial (such as a typographic error). Some organizations flag all updates, others make a judgment call about what is considered a substantive update.