Revision and new page patrolling is a feature enabled on some wikis, including the English Wikipedia. Revision patrolling, enabled by default on MediaWiki installation, is switched on using $wgUseRCPatrol, while new page patrolling, also enabled by default, is switched on using $wgUseNPPatrol.
Pros and cons
The merits of patrolling are sometimes debated. Marking pages as patrolled is an extra step in reviewing pages, and bright red exclamation points in the RecentChanges feed can be distracting. It is also unclear whether other editors should pay attention to whether another user has marked a revision as patrolled, since who is to say that patroller's opinion can be trusted.