For the guideline to evaluate rough consensus, see WP:ROUGH CONSENSUS.
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The official policy related to applying and removing semi-protection is located at Wikipedia:Protection policy. This rough guide describes how the semi-protection policy is currently being applied by administrators. Every case is different, and 'passing' every criterion does not mean a page must be protected; administrators are at liberty to use their discretion.

General considerations

An editor considering requesting semi-protection for a page at Wikipedia:Requests for page protection (WP:RFPP), and an administrator considering applying semi-protection must assess each situation individually before deciding on a course of action.

  • Is the problem vandalism or an editing dispute?
  • How much vandalism is taking place?
  • Is the vandalism from a wide range of accounts/IPs?
  • Are any constructive edits being made to the page, especially from unregistered users?
  • Is the problem on a high-profile, widely watchlisted page?
  • Does the problem have a detrimental effect on how Wikipedia looks to the public?
  • Is the subject of the page a living person?
  • What is the quality of this article? Higher-quality articles are more damaged by vandalism than similar low-quality articles, and there is also less likelihood that a given edit will improve the article. In addition, since higher-quality articles are more complete, there is less likelihood that the article will need to be edited in the first place.

Criteria for semi-protection

Articles subject to heavy and continued vandalism can be semi-protected. There are no explicit rules that determine the level of vandalism that is necessary to trigger semi-protection. Administrators should use their best judgment to determine if semi-protection is warranted. Here are some criteria that may be helpful to determine if semi-protection is appropriate:

  • All or almost all of the vandalism is coming from unregistered users.
  • Unregistered editors should be making very few quality contributions to the article compared to the amount of vandalism coming from unregistered editors. The negative effects of semi-protection on discouraging positive contributions should be more of a concern than the positive effect of decreasing vandalism.
  • There are regularly many new vandals, therefore it would be a huge unending task to notify and warn all the vandals individually.
  • According to Wikipedia:WikiProject Vandalism studies/Study1#Conclusions, on average 5% of edits to a page are vandalism. So, 5% is the level of vandalism to be expected, and semi-protection should not be applied in this case. More than usual levels of vandalism occur when anything over 5% of edits constitute vandalism. If each vandal edit was followed by a revert, without any further edits to the page, then 50% of edits would be vandalism. More than 50% is rare, but may occur when multiple vandalism edits are reverted by a single edit. The higher the percentage of vandal edits, the greater the need for protection.
  • Consider a lower threshold for protection for articles on living people as vandalism is potentially more damaging in these cases.

Determining the duration for semi-protection

If semi-protection is to be tried, its first application should be for a short duration, a few days or a week. If vandalism continues after the protection expires it can be added for a longer duration. At some point an administrator might determine that the semi-protection should be made indefinite. This is reserved for only the most vandalized articles, and any administrator is free to lift 'indefinite' protections.

  • Pages that are indefinitely semi-protected must have been semi-protected previously. This shows that the problem is ongoing, and that temporary semi-protection does not have a lasting effect.
  • Vandalism that resumes very shortly after semi-protection is removed demonstrates that the page is a popular target for random vandalism. Such pages are likely candidates for indefinite semi-protection.
  • If vandalism is related to a current event, the semi-protection should be lifted after the event is out of the public eye.
  • The only way to determine if ongoing semi-protection is still necessary is to remove the protection and see if the vandalism resumes at previous levels. For this reason, all pages that are indefinitely semi-protected can have their protection removed from time to time. The administrator should monitor the page after removing the protection.