Limits to configuration changes/Update 2019
This page is intended to be a more "digestible" version of Limits to configuration changes. It was initially written by Martin Urbanec, one of the volunteer system administrators. As of August 2019, the page is still under construction (and has been edited by others).
Sometimes a community demands a wiki configuration change that is technically feasible to implement, but is rejected by the system administrators, who hold the ultimate authority over MediaWiki configuration.
This page serves to document how system administrators usually react to certain types of requests, and what the community should expect from them. As such, it doesn't need to contain all rejections from system administrators, just ones that are likely to be requested again. If you feel that a rejected request should (or should not) be listed here, please update this table as appropriate, even if you're not a system administrator. If you're not sure, leave a comment on the talk page.
This section lists requests that will be declined right away. System administrators prohibit these changes to protect Wikimedia's founding principles and core values, as well as to protect the integrity of the projects in general. Wikimedia Foundation's Legal department also prohibits some changes for legal reasons.
|Type of request||Example request||Reason||Notes|
|Changes that make the wiki less open||Remove a log from Special:Log||Transparency is a non-negotiable principle of MediaWiki. Feature requests are recommeneded if a log is bothering the community and features to filter it out don't exist yet.||This doesn't include hiding a log by default from Special:Log, but only cases when the log would not exist at all.|
|Enable CAPTCHA for all edits of non-confirmed users permanently||This configuration places an undue restriction on new contributors, given CAPTCHAs are here to help with abuse and vandalism, not to serve any other purpose. System administrators deemed that this is incompatible with Wikimedia core values, and as such, prohibited this change.||Please note this is about enabling CAPTCHA for all edits permanently. If your wiki is experiencing an immediate and unmanageable abuse/vandalism, please do reach out to the system administrators. This would be considered as a security incident report. As such, please use security report form. This will create a task to be visible to Wikimedia Foundation Security department, as well as relevant system administrators. They will jointly assess your issue, decide on potential restrictions and implement them. You do not need to recommend any solutions.|
|Changes that are technically impossible||Changes to the naming of timezone options||MediaWiki uses the PHP timezone database, which uses the IANA Time Zone Database. As such, it is technically and physically impossible to change the names of any timezone options. It's only possible to change which timezone is the default in your wiki via the $wgLocaltimezone variable.|
|Proposed changes with security and/or legal liability issues||Allow non-admins to view deleted stuff||WMF Legal banned non-admins not passing RFA-comparable process from viewing deleted content; see Wikipedia:Viewing deleted content.|
|Allow non-stewards to manage CheckUser/Oversight permissions||Only stewards are allowed to manage those highly restricted groups; local wikis are not allowed to customize this.|
|Add hideuser right to non-oversighters||By policy, it is the task of oversighters to hide things from the public. Oversighters sign confidentiality agreements and are legally required to keep the information private, while this is not true of administrators and others.|
|Grant Interface admins other permissions||The purpose of interface admins is to make fewer users able to edit CSS and JS pages. Granting other rights to this group may encourage wikis to grant this right when their intention is different.|
|Allow administrators to grant bot, administrator or interface admin rights||Rejected because granting and removing those flags is a task for bureaucrats where present, or stewards. Interface administrators also have highly sensitive permissions (to edit CSS and JS pages) and requests for granting must be carefully considered. As such, it is necessary that only bureaucrats or stewards handle this task.||Wikis that currently don't have any bureaucrats and feel they are big enough to handle this themselves are recommended to elect bureaucrats instead.|
|Allow bureaucrats to remove bureaucrat rights||This is to protect the safety of the projects. Since bureaucrat permissions are higher than those of administrators, only stewards are allowed to do this.||Bureaucrats on all private wikis can remove bureaucrat status, but that's because private wikis are managed by dedicated groups and serve special support purposes rather than host content.|
|Changes to use unsupported technologies, or abuse them in unsupported ways||Installation of LiquidThreads||Although the extension is installed on some WMF wikis, it was considered unmaintained and incomplete — and future switching back from LiquidThreads to normal talk pages was deemed too difficult. So the existing instalations are preserved, but no further instalations are allowed.|
|Enable VisualEditor on talk pages||The visual editor is not built to support editing talk pages. As such, enabling the visual editor in a talk page namespace is likely to not always work as expected by the community. To save developers from bug reports about something that's not supposed to work in the first place, enabling VisualEditor on talk pages has been prohibited.|
|Uninstall Flow||Uninstalling Flow (now known as Structured Discussions) is a hard task, given how complex Flow is. For this reason, requests to do so will be declined. Wikis can request that Flow be set to "read only" if they don't want use it anymore.||To avoid future problems, Flow was uninstalled in March 2018 from all wikis where it had zero topics (see phab:T188812).|
|Installing extensions/skins that aren't already installed on at least one Wikimedia project||To protect the security of the Wikimedia infrastructure, all extensions, skins and other components running in it must pass security, performance and other reviews. Extensions that are not already installed on at least one Wikimedia project won't be considered for installation until they pass such reviews.||See mw:Review queue|
|Changing the default skin on any individual wiki||Wikimedia should have a standardized look globally across all our projects. It has been decided that Vector will remain the default skin on all Wikimedia wikis unless the decision is made to change this globally.||Changing the default skin on all Wikimedia wikis is certainly not prohibited, but would be extremely difficult to accomplish, and would be centrally led. Not only would this require consultation with all affected communities before such a decision could be made, but a massive effort would also be required to make all the necessary changes "behind the scenes".|
Changes that are likely to be declined
This section lists changes that are not strictly prohibited, but are likely to be declined unless special evidence can be presented to convince system administrators that the changes are necessary.
|Type of request||Reason|
|Disable non-autoconfirmed page creation||This configuration places an undue restriction on new contributors. Sysadmins will resist such a request unless the wiki in question (1) is prepared to handle drafts in a timely manner, (2) has a well developed editing and administrative community, and (3) has established an unusually broad consensus for the change. The first two points can be addressed by appealing to the wiki's size: the number of active editors, sysops, bureaucrats, and other functionaries should be similar to "big wikis", otherwise a very good explanation will need to be given as to why the request should be accepted. The third point can be satisfied by a carefully discussed on-wiki RFC, with the closing administrator explaining the consensus in the relevant Phabricator task; if the consensus does not look particularly strong on its face (note that there may not be any sysadmins who are able to read the local language of the wiki), the admin will have to explain why it nonetheless should be considered sufficiently broad.|
|Allow bureaucrats to remove administrator permissions||While bureaucrats on some wikis can revoke the administrator flag, at most wikis this is the responsibilty of stewards. In order for this kind of request to be accepted, the wiki should be large—with multiple active bureaucrats—and be able to demonstrate a real need for the change. In smaller wikis this ability is prone to abuse by bureaucrats wishing to usurp the power of the community to decide on issues of adminship.|
|Special groups on small wikis||System administrators may consider wiki size before adding a special user group. Such requests sometimes seem to be motivated by the mere desire to have something that bigger wikis have rather than an actual need. For example, members of the rollbacker group are given a tool that allows them to do with one click the same thing ordinary users can do in a series of steps (revert multiple edits by the same user); in small, low-traffic wikis this speed increase may not be necessary and must be weighed against the potential for abuse. Also, sometimes requests to create a custom group can instead be implemented with an existing user group (such as autopatrolled). In the interest of manageability, sysadmins will not create a new group if an alternative approach can be found.|
Changes made by the system administrators at their own discretion
As said at Requesting wiki configuration changes, the ultimate authority on Wikimedia configuration lies with the system administrators. This is because only system administrators can edit it, and as such, are fully responsible for it, and because no one can be made fully responsible for something without also granting full authority over the same something. As such, system administrators can not only reject requests, but also change configuration on their own. This section aims to explain and document why this might happen, but given the world can be hard to predict, it isn't (and can't be) complete by any means. In this section, "changes made by the system administrators" are called "measures" for the purpose of simplicity.
Measures can be both permanent and temporary, althrough temporary ones tend to be more frequent. System administrators do their best to limit temporary as much as possible, while still keeping the measures effective. Especially temporary changes can be communicated with the community in full, meaning the community would recieve overall explanation that explains why the measure was taken without going into technical details, partially, meaning the community would be informed that a measure was taken, but not why, or not at all, while the community won't recieve any information. Same as with duration, system administrators do their best to give less information only when it is necessary, but given the nature of the measures, they also err on the side of caution to protect the security of Wikimedia infrastructure. As such, system administrators might decide to not inform community, or to give little information, when it later shows it wasn't necessary. While this should happen as infrequently as possible, it can happen, and cannot be prevented.
Measures are mostly taken to protect the security of the Wikimedia infrastructure, but infrequently, can happen for other reasons as well. The other reasons aren't mentioned here, because it is hard to predict them, and this section is (as of 2019) relatively new, as it was written in late 2019. As time goes, technical community members (who may or may not be system administrators) will do their best to update this section. Examples of cases warranting taking measures can include exceptionally high level of vandalism, other attempts to disurpt Wikimedia movement and the like.
Temporary measures can include (but aren't limited to) decreasing the limit of accounts created from one IP address, requireing CAPTCHAs for all edits and the like. Permanent measures can include (but not limited to) taking away certain ability from administrators in favour of dedicated group or deciding that two factor authentication is mandated to be in an user group.