Pending changes allows reviewers to check edits before they go live to the general public. Consensus during discussions leading up to the eventual roll-out of pending changes level 1 (only affecting edits by IP and new users) was that to avoid problems, pending changes should be limited to the following:

• Blatant vandalism
• BLP violations
• Copyright violations
• Relatively low-profile pages

These restrictions are all based on potentially negative effects that were identified during discussions and trials, including feedback from foreign Wikipedians who have worked with sighted revisions. Proper use of PC will avoid creating the following side effects.

The main reason for the above limitations is the position that reviewers find themselves in. Those working through a reviewer backlog are often not subject matter experts. They are not in a position to review edits for validity. If they did engage in such behavior, they risk immersing themselves in content disputes in every article they touch. We want to encourage reviewers, not punish them for volunteering to review edits by immersing them into disputes. By sticking to the clear cases, we avoid this negative effect.

Rejecting unapproved edits is akin to rollback; it's a summary rejection of the edit without comment. This sort of harsh treatment has been reserved in the past for edits that are clearly problematic, not ones that are potentially made in good faith. This is another reason that PC is only used for clear-cut violations. Lesser violations or problems should be first accepted, and then edited or reverted with an appropriate summary. If you would not have used rollback on an unapproved edit, then first approve the edit and then deal with the problem.

Pages that are frequently edited are poor candidates for pending changes protection: the ongoing page edits can result in a long backlog of pending changes. In addition, the current implementation of pending changes protection is not effective for search engines: the API used by search engines to access Wikipedia pages always returns the most recent version, whether or not it has been approved, and so problematic edits will show up immediately in search engines. For these reasons, avoid using pending changes protection for frequently edited pages.