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This guide was written by a Commons oversighter, but it might be helpful even if you come from a different wiki. Most of the procedures described here can apply to all MediaWiki-based sites.
From now on, the word "oversighters" will mean users with the oversight permission (see definition); "suppression" will mean hiding data from regular editors and administrators.
Note: This is not an official Commons guide, but an attempt to document bus factor. It comes with no warranty, so make sure you know what you're doing!and to increase our
File suppressions are the most common suppressions on Wikimedia Commons, simply because of the scope of this project. Depending on the situation, there are several ways to achieve the same result; this section will cover only the most popular ways.
Suppressing all file revisions
Suppressing existing files is easy:
- Go to the regular deletion menu (or press
alt + shift + don your keyboard);
- Add a reason for the action in the "Other/additional reason:" field, make sure to tick the "Suppress data from administrators as well as others" option and press "Delete page".
In this case, it is very important to double-check if the "Suppress data from administrators as well as others" option is ticked. If you do not tick it, you'll need to restore the file, repeat the steps again, and suppress a few more log entries than normal; your actions will also be temporarily visible to non-oversighters.
This basic functionality has a disadvantage: it does not allow you to choose what property (edit summary, user name/IP address or file revision) to suppress, but simply suppresses them all. It hides all edits made to the file page from users' deleted contributions and suppresses all file revisions. However, it does not influence previous log entries for the file, so you might have to suppress them, too (see #Log-related suppressions).
This is by far the most common example of suppressions done on Commons. Due to the small number of local oversighters and the number of files, it is impossible for us to patrol all uploads at all times; therefore, most files are already deleted before we see them.
There are two ways of suppressing files that had already been deleted:
- The quick way: simply restore the file and suppress it directly from the deletion menu (see #Existing files and #Log-related suppressions for more details). This method has a few disadvantages: (1) it makes the file temporarily visible to non-administrators, (2) it doesn't allow you to choose what properties to suppress, and (3) it creates a new deletion (restoration) log entry; on the other hand, it is quickest and lets you suppress all file revisions and edits in one action.
- The slow way. This method doesn't restore files and allows performing per-property and per-revision suppressions, but takes a lot of time and creates a number of entries in the suppression log.
- From the file undeletion page (Special:Undelete), go to the File history section and click on (show/hide);
- Next, tick the "Hide file content" and "Suppress data from administrators as well as others" options. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision". If necessary, tick the other options (edit summary or username/IP address);
- If required, repeat this step for the remaining file revisions and edits. Note: If you had suppressed all file revisions and realised that you need to suppress all edits, too, don't suppress them one by one; just restore them and suppress them in the usual way (see #Existing files);
Suppressing specific file revisions
To suppress a specific file revision:
- On the file page, scroll down to the "File history" section and press (show/hide) next to the thumbnail of the file revision you want to suppress;
- Next, tick the properties you want to suppress and the "Suppress data from administrators as well as others" option. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
- Note: If you want to suppress the contents of the "Comment" box, for example because they reveal the real name of a user, tick the "Hide edit summary" option. However, due to bug #38497, you also need to remember to suppress the upload log entry of the file and the edit summary on the history page. See #Log-related suppressions and #Suppressing previous revisions for instructions on how to do that.
As with regular page revisions, you cannot suppress the current revision of a file. If, for example, the file that you need to suppress reveals personal information of a user (through their user name, upload comment or through the file content itself), you need to upload a new version of the file, and then suppress the previous one.
This is most common when suppressing previous versions of files that reveal non-public information through their Exif data; see the section below for details.
Removing Exif data
Users sometimes request that we suppress file revisions that reveal their non-public private information (real names, e-mail addresses or geographical coordinates) through the Exif data. This is difficult, as there is no built-in mechanism in MediaWiki to remove this data; therefore, it can only be done by uploading a new version of a file and suppressing the previous one(s) (see above).
There are different ways to change Exif data, depending on your operating system and tool preferences. Here's how it can be done on a Unix-like system using exiftool via the command line:
Get a full list of all Exif tags for the file:
$ exiftool -s [YOURFILE]
To delete specific tags, run:
$ exiftool -Tag= -DifferentTag= [YOURFILE]
As you can see, exiftool can remove multiple tags in one command. Remember that exiftool tag names never contain spaces and that some of the tags cannot be changed (see a full list of).
Suppressing previous revisions
Suppressing previous revisions of a page, or properties of a page, is possibly the easiest action an oversighter can take.
To suppress a single revision:
- Go to the history page (or press
alt + shift + hon your keyboard);
- Select the revision and press "Show/hide selected revisions";
- Next, tick the property you need to suppress and make sure to tick the "Suppress data from administrators as well as others" option. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
Suppressing multiple revisions is achieved in the same way:
- Repeat steps 1 and 2 as above;
- Then, tick "Yes" next to the properties you want to suppress, and make sure to tick the "Suppress data from administrators as well as others" option. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
However, this only works if you want to suppress the same properties for all revisions involved. If you want to suppress a certain property (e.g. text) of multiple revisions and an extra property (edit summary) in just one revision, you can do that in two steps:
- Select the relevant revisions and suppress their properties (text) as needed;
- Then, select the remaining revision, tick both the text and the edit summary options and proceed as usual.
This method allows you to perform the suppression in just two actions. Of course, it is possible to suppress the relevant revisions one by one, but it takes longer, creates a number of entries in the suppression log and is harder to undo.
Suppressing current revisions
If you need to suppress certain properties of a current page revision (edit summary or user name/IP address):
- Go to the history page (or press
alt + shift + hon your keyboard);
- Tick the current revision and press "Show/hide selected revisions";
- Next, tick the property you need to suppress (or both of them) and make sure to tick the "Suppress data from administrators as well as others" option. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
This method does not work if you need to suppress the text of the current revision, as MediaWiki is unable to hide the current revision of a page. In such a situation:
- Edit the current revision, remove the text you want to suppress, and save your edit;
- Suppress that previous revision as usual, making sure to tick the "Hide revision text" option so that no diffs are visible for non-oversighters (see #Suppressing previous revisions).
Most of the time, this method is used to suppress IP addresses of registered Wikimedia Commons contributors who made edits while logged out; see #Hiding IP addresses for more details.
Log entries are usually suppressed in addition to file or page suppressions. Suppression can remove all sorts of data from all kind of logs, but is most often used to hide upload and (un)deletion logs of already suppressed files; this way, they cannot be found outside of Commons.
To suppress upload and (un)deletion log entries of a file:
- Go to Special:Log and paste the file name into the "Target" field;
- Tick all entries and press "Show/hide selected log entries";
- Depending on the issue, tick the appropriate properties (action and target, edit summary or username/IP address);
- Make sure to tick "Suppress data from administrators as well as others"; add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
Hiding IP addresses
This is possibly the most common example of text-related suppressions performed on Commons. However, the general rule is that we do not suppress IP addresses of users if they don't request it themselves, as some users are fine with their IP addresses being visible (for example if they change often).
If a contributor accidentally edited a page while being logged out:
- Go to the history page (or press
alt + shift + hon your keyboard);
- Select the relevant revision(s) and press "Show/hide selected revisions";
- Tick the "Hide editor's username/IP address" option and make sure to tick the "Suppress data from administrators as well as others" option. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision".
However, if the edit was made to a discussion page and contains a signature with the IP address inside the revision text, you'll need to suppress that revision text, too:
- If the user logged in again and changed their signature, this can be done by ticking the "Hide revision text" option as in step 3 above;
- If the user has not yet changed their signature, you need to do it for them. After saving the edit, perform all steps as above; in step 3, tick both the "Hide revision text" and "Hide editor's username/IP address" options so that you suppress both properties in one action.
This way, you not only suppress the IP address from the history page, but also make the diff between the two revisions (one with the IP address, the other with the regular user name) visible to oversighters only.
Abuse filter actions
Occasionally, edits made by accidentally logged out editors are caught by our abuse filter rules, which records them in the abuse log for everyone to see. Since the log is part of the AbuseFilter extension and not of the MediaWiki software itself, hiding (not suppressing) its entries is different than usual.
To hide an IP address from an abuse log entry:
- On the abuse log page, click on "adjust visibility" in (details | examine | adjust visibility) next to the relevant log entry;
- Add a reason for your action in the "Reason:" field, make sure to tick the "Hide this entry from public view" option and press "Submit".
Unlike regular log entries, it isn't possible to perform per-property actions on abuse log entries (for example to hide only the IP address while leaving the target page and filter number public); you can only hide the entire entry.
Since MediaWiki 1.18, it is possible to entirely hide a user name on a wiki. This is useful when dealing with user names that leak non-public personal information or are insulting or harassing someone.
To hide a user, go to their block page (directly from a log, page history, or through their user page):
- On the block page, set the expiry time to "indefinite" and add a reason for your action in the "Reason:" field;
- Make sure to tick the "Hide username from edits and lists" option, tick other options as necessary, and press "Block this user";
- Next, confirm the block by ticking the "Confirm block" option and press "Block this user" again.
Ticking the "Hide username from edits and lists" option makes your block part of the suppression log and removes the user name from all automated logs and file pages, history pages, deleted contributions and recent changes.
All actions performed through MediaWiki, including suppressions, are reversible. With a few exceptions, all actions can be reverted directly from the suppression log:
- For file- and page-suppressions, just click on the (change visibility) link and untick the options you want to unsuppress. Add a reason for the action in the "Other/additional reason:" field and press "Apply to selected revision";
- For blocks with the "Hide username from edits and lists" option set to "on", go to the list of blocked users and paste the user name into the "IP address or username:" field;
- Click on "change block" in (unblock | change block), and add a reason for the action in the "Reason:" field. Untick the hiding option and press "Re-block the user with these settings".
If you mistakenly suppressed an action caught by an abuse filter rule, reverting yourself requires one more step than that:
- On the suppression log page, click on the event link (it will look similar to Special:AbuseLog/123456);
- Next, click on "adjust visibility" in (details | examine | adjust visibility) in the details box;
- Enter a reason for your action, untick the "Hide this entry from public view" option and press "Submit".
Wikimedia Commons oversighters have developed a habit of informing one another about their actions. This provides a possibility for immediate peer review of suppressions and lets the rest of the team stay up-to-date about what's going on. It also allows commenting on recent actions if necessary.
The main method of communication between oversighters is themailing list, to which we all are subscribed. There is no need to go into extreme detail, as we can all see what exactly had been suppressed; a short description of what you did, why you did it and—if applicable—what errors you saw is just fine. The mailing list archives are kept on a Wikimedia Foundation server, but the e-mails are forwarded to various addresses, so please do not include the information you suppressed inside your message and use links instead.
Since November 2012, following the example of the English Wikipedia Audit Subcommittee, we have been keeping rolling six month statistics of oversighters' activity on Commons. This increases the transparency of our actions and gives the community an overview of what's happening.
As of December 2020, the statistics are compiled by odder (talk · contribs) at the beginning of each month using data from the suppression log. For these statistics, one action equals one log entry and does not mean one revision, user, file or log entry, as one action can affect multiple items. Actions done by Wikimedia Foundation staff and Wikimedia stewards are not included there.
Getting help with suppression-related issues can be hard. Due to the nature of our actions, there is no public forum to discuss them, and their small scope makes it unreasonable to have a private wiki; therefore, different tools are used.
For non-urgent matters, the best way to get help or receive feedback is to use the IRC channel #wikimedia-commons on Freenode ( ) and contact them privately. If none are available, contact oversighters from other Wikimedia projects at #wikimedia-privacy — please remember that this channel is private and requires invitation or being on its access list; speak to Barras, DerHexer, guillom or Trijnstel to be added.. When the request you are handling requires immediate action, the fastest way to get help is to look for other Commons oversighters on the
If you are suppressing potentially illegal content, you should check global contributions of the user involved; use the stewards on #wikimedia-stewards ( ) by posting
@steward + your request to the channel, and ask for the account to be locked. This way, the user will be signed off from all current sessions and won't be able to log in to the account again (details).
Due to the effect that suppression has on the visibility of data, all requests have to be analysed carefully. You should usually check the oversight policy before doing anything. You can, however, simplify this process by following this advice:
- Don't be afraid to deny requests. As mentioned above, the effects of suppressing data are severe, since there are currently only about 50 users with the
suppressionloguser right on Commons (including stewards and Foundation staff). Some of the requests (for example to remove insults or swearwords) are better served with regular revision deletion, e.g. without ticking the "Suppress data from administrators as well as others" option. However, our general rule is…
- Better be safe than sorry. All actions we take are based on our experience, intuition, personal impressions and opinions. When it comes to potentially illegal content, it is therefore better to act pre-emptively than not to act. For non-urgent issues, try consulting other oversighters first, but if your instinct tells you to act, just go ahead and remember that…
- Nothing is irreversible. However trivially this sounds, MediaWiki is designed so that nothing you do can cause irreversible damage. If you suppressed a log entry, file, revision or property of a revision (edit summary, user name/IP address or revision text) that should not have been suppressed, go ahead and revert your actions.
Contacting Wikimedia Foundation
On rare occasions, you may find that you require help from Wikimedia Foundation staff.
If the situation involves a threat of harm to life, limb or property, immediately e-mail
firstname.lastname@example.org. A team from the Foundation checks this address 24/7; they will confirm they got your message and ask questions if necessary.
Child protection/illegal content
If you suppress content that is potentially illegal, make sure to e-mail
email@example.com straight away. This way, the Trust and Safety team can assess the situation and take their own actions. Don't worry about time zones, as they also check this address 24/7. If you're informing the other oversighters about what you did, just add this address to the CC field of your message.
If the situation does not involve illegal content or a threat of harm to life, limb or property, contact the Trust and Safety team at
firstname.lastname@example.org for advice and assistance.
As all software, MediaWiki can contain bugs. Unfortunately, even the revision deletion functionality that we use in our work has bugs! If you see a bug when trying to suppress data, pleaseto see if the problem hasn't been reported already. Some of the bugs contain comments describing currently used workarounds which you might find helpful.
For bugs that leak personal information, please submit your report with the security level set to Software security bug; in such case, feel free to CC other oversighters or describe the problem on the mailing list (as security bugs are not publicly visible).