Help:Administrator's Handbook/Block

Blocking a user prevents the user of a certain account or IP address from editing for a determined period of time, and is one of the most heavy-handed things you can do as an administrator, and the one that can cause the most damage. An administrator must therefore be cautious in using this power. Often a user will spend quite a bit of time building up a reputation under a particular user name, and by blocking that user they will not be able to edit from their account. Blocked users can still edit their user talk page unless these pages are protected and the user doesn't have sysop or higher privileges.

It is also possible to block IP addresses from being able to edit text. This does not stop a registered user on that IP address from being able to log in, but only stops anonymous users from using the edit functions. If there is a problem where a registered user is unable to access the wiki due to an anonymous IP block, then the user must unblock that IP and reblock with anonymous users only checked. An IP can be prevented from creating an account by checking the "Automatically block the last IP address used by this user, and any subsequent IP addresses they try to edit from" option.

Performing the block
Start by going to Special:Block. Put in the user name or IP address to be blocked in the top box. In the drop-down menu, select how long you wish to block the user. State your reason below.

If you want to block edits on an IP address, whether a user is logged on or not, uncheck the "Block anonymous users only" box. To allow IP addresses to create accounts, uncheck the "Prevent account creation" box. To ensure that a user does not simply create another account for vandalism, check the "Automatically block the last IP address used by this user, and any subsequent IP addresses they try to edit from" box. To prevent a user from sending an e-mail or to watch the blocked user's user and talk pages, check the respective boxes.

When to block
Blocking policy varies from project to project, but it generally applies to the following categories of user:
 * Persistent vandals/trolls
 * Spammers
 * Threats or harassment
 * Persistently adding copyright violations
 * Inappropriate user names

Options

 * Expiry sets a time after which the block is automatically lifted by the MediaWiki software. The dropbox offers several frequently-used time periods, such as "24 hours", "1 week", and "1 month". (Please see note below about block lengths.)
 * Block anonymous users only allows users from a blocked IP address to edit using a registered account, only restricting the edits of anonymous users. (This option is not available when blocking a registered username.)
 * Prevent account creation prevents the creation of new accounts from a blocked IP
 * Automatically block the last IP address used by this user, and any subsequent addresses they try to edit from blocks any IP used by this account

Unblocking
In order to unblock an account (to allow editing or increase the period of the block) go to Special:Ipblocklist where the option is available.

Length of block
The priority must be to minimize damage to the wiki. However when there is time or on review afterward some or all of the following may be helpful in looking at the length of the block.
 * 1) User contributions. Bear in mind that if a page is deleted it will not be in the contributions. (This is often the case with spam bot-type pages.)
 * 2) Block log history. This may give guidance on previous blocks.
 * 3) User talk page on Wikipedia. Given the level of traffic on WP compared to other wikis this may have a useful history of both editing patterns and warnings.
 * 4) Block log on Wikipedia. Again this may give guidance on the level of nuisance and block period.
 * 5) Ask around! It's always worth it.

Conflicting block lengths
If a particular user or IP is blocked more than once simultaneously, the MediaWiki software will honor the block that expires the soonest. (This may or may not be the shortest block.) In this case, the sysops who placed the blocks should contact each other and decide which length is most appropriate under the circumstances.

Indefinite blocks
The "indefinite" option in the Expiry field allows a sysop to block a particular user or IP without specifying an expiration. This block is effectively permanent, but it can be lifted at any time by any sysop. Indefinite blocks should be used sparingly on IP addresses because IPs tend to shift from user to user over time.

Custom block lengths
The "other" option in the Expiry field allows a sysop to define either a custom block length or a precise date and time when the user or IP will be able to edit again. Custom values must be entered in the GNU date input format.

Range blocks
The MediaWiki software allows sysops to block entire ranges of IP addresses. Using CIDR notation, enter an IP range between /16 and /31 (inclusive; MediaWiki does not support blocking larger ranges). If you are unfamiliar with CIDR and binary arithmetic, then you should not block ranges.

A properly-applied range block will remove editing privileges from all persons who connect from an IP in the affected range. As a result, it may unintentionally block valued contributors, so it may be worthwhile to consult a checkuser before applying a range block.

Range blocks are a drastic measure, and should only be used for brief periods as a last resort. Poorly-applied range blocks can shut out entire nations!