Wiki Team/Guide/Patrolled Edits
Some users can be given the patrol permission, which allows them to review the edits made by others.
If you have the ability to patrol edits, then in the list of Recent Changes a revision which has not been reviewed will be marked with a red exclaimation mark "!".
When you view the differences between versions of an unpatrolled article you will find in the column headers a link which say
[Mark as patrolled]
You should only click on this link if you have reviewed the changes to the article and found nothing clearly unacceptable, such as vandalism.
Patrolling is not a substitute for substantive editing. It's just a way to keep vandalism in check.