If you’re reading an article in Wikipedia and see vandalism, unencylopedic links to commercial or personal Web sites (linkspam), or some other blatant policy violation, your first impulse may be to click “edit this page” and fix the problem. Resist that urge. Manually deleting offending text is error-prone and time-consuming. And, worst of all, if the vandal or spammer deleted or overwrote text while doing the dirty deed, simply removing the problem still leaves the article damaged, since good information is now missing.
Instead, use options in the page history to revert the problematic edit(s). Reverting restores any content that was overwritten or deleted, and removes offending text, putting the article back to what it was before it was vandalized or spammed. Reverting is one of the most powerful features of wiki software. This section shows you how to do a revert in just a few easy steps.
Note
On the other hand, reverting isn’t always the answer. If another editor adds text that you think is verbose, or is full of spelling errors, or has invalid citations (to name just a few possible problems) to an article, you should edit, not revert. Keep what’s useful, improve what’s marginal, and delete what’s not useful. Restrain your reverts to bad faith edits—clear vandalism and spam, and to clear policy violations, and you’ll get along well with all the other editors helping to improve Wikipedia.
Until November 2006, Wikipedia had only one way to revert a problematic edit—change the damaged page so that the current version of the page was reset to an older, good version. If the last good version was, say, as of Wednesday at 10:00 UDT, then the software would essentially copy that version, overwriting all the changes (edits) made after that time and date.
For the majority of vandalism cases, this kind of revert is sufficient, because good editors check page histories for signs of likely vandalism before editing, and because anti-vandalism activities (which you can read more about in Chapter 7) identify most vandalism shortly after it appears. But the major drawback of this approach is clear—what if one or more constructive edits came after the problem edit occurred?
The new option—undoing one or more consecutive edits that aren’t the most recent—offers a way off the horns of that dilemma. It’s now usually possible (more details below regarding “usually”) to get Wikipedia software to revert interior edits—ones that don’t include the most recent edit. Unlike a revert, an undo retains good edits that occurred after the problem edit, creating a truly new version of the article.
Say you’re looking at five edits of an article, one per day starting on January 1. The edits on January 4 and 5 were constructive; you want to keep those. The edits on January 2 and 3 were vandalism. The edit on January 1 was constructive, and there’s no vandalism prior to that. Using the revert approach, you’d have to revert the article to the last good version (the one on January 1), and then manually add back the good edits of January 4 and 5. That would be the only way to avoid penalizing the editors who missed the vandalism but added good information. In this case, you now can use undo to remove only the two vandal edits.
On the other hand, if you want to revert only the most recent edit, or the last few edits (say the edits from January 2 through the 5 were all vandalism), then you can use either revert to a prior version or undo. Both are four-step processes that take roughly the same amount of time. As a bonus, if you’re reverting only one edit, the undo option has the advantage of automatically adding information to the edit summary.
So if undo works all the time, while reverting is useful only sometimes, why learn both processes? There’s one advantage to using the classic revert: Unlike an undo, with a revert it’s impossible to have an edit conflict (Dealing with an Edit Conflict). If you’re reverting vandalism on a high-traffic page (the Main Page is the most prominent example), an edit conflict could significantly slow your fixing of some highly visible vandalism. So knowing how to revert can still be useful for relatively rare cases.
Doing an undo is a four-step process, starting from the history page. (If you’re starting from a diff page (Seeing What Changed), then just skip step 1.)
Select the edit(s) you want to undo.
If you’re reverting only one edit, click the “undo” link (on the far right) of the problem edit’s row. (This step saves you from having to click “undo” in step 2, by the way. If you clicked the “last” link, by contrast, you’d have to click “undo” in step 2.)
If you’re going to undo multiple consecutive edits, use the radio buttons (Figure 5-4) to create a diff.
Tip
It’s best to first try to undo an entire group first (it’s faster). If that doesn’t work, then try to doing “undo” for smaller groups, or individual edits.
On the diff page, click “undo” at upper right, above the right column of text (Figure 5-3).
The Wikipedia software tells you whether it can revert the edit(s). The more consecutive edits you’re trying to undo at the same time, assuming none is the current version, the less likely that the software can actually do an undo of the whole group.
Most of the time, you’ll see the following message at the top of the page: “The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.” If you see this message, you should take a quick glance at the comparison (two columns, just like Figure 5-3), and then skip to step 4.
If the top of the page reads, “The edit could not be undone due to conflicting intermediate edits”, and you’re looking at an edit window (don’t start editing), then turn to Plan B:
If you were trying to revert multiple edits at the same time, try doing them one by one, starting with the edit that changed the largest amount of text. You may find that you can still undo most of what was done improperly, even if you can’t undo it all.
If you were trying to revert a single edit, and the undo can’t be done, then you’re going to have to dive in and start editing. Click the Back arrow on your browser (or Back button on your keyboard, if you have one) to return to the diff. Then open the current version of the page (or current version of a section, if that’s all that needs editing) in a different window, and use the diff as a guide to manually edit the current version.
Tip
If you’re forced to do manual cleanup, you can still avoid retyping a lot of text. When you find a chunk of text that was improperly deleted, copy it where it shows in the diff—by highlighting the text, and then pressing Ctrl+C (⌘-C on a Mac)—and paste it where you’re editing the current version. Clean up the pasted text if necessary.
Edit or add to the edit summary.
If you undid only a single edit, you’ll see an automatically generated edit summary below the editing window like the following:
([[WP:UNDO|Undid]] revision 132832143 by [[Special:Contributions/Name Of Editor|Name Of Editor]] ([[User talk:Name Of Editor|talk]])
That intimidating text looks like the following when someone looks at the page history:
Undid revision 132832143 by Name of Editor (Talk)
Since the edit summary consists of a maximum of 200 characters, there’s a limit to how many words you can add to the edit summary after the computer-added text (131 characters in this example, counting blank spaces—which do count). You have enough room to add, say, rvv (meaning “revert vandalism”) or rv linkspam. If you’re not reverting vandalism, however, then your undo may not be clear to other editors, and you should explain it in the edit summary. If you need more space, you can remove the link to the editor’s talk page; in this example, delete ([[User talk:Name of Editor|talk]]). (Other editors can easily get to that user talk page via the second wikilink in the edit summary, the one to the user page.)
If you undid more than one edit simultaneously, then the software doesn’t put anything in the edit summary, so you need to. Be brief but clear; for example, rv multiple vandalism by two different users on 10 May, or rv three edits by Name of Editor—per Arbitration Committee decision, editor is not allowed to edit this page.
Below the editing window, click the “Save page” button.
Normally, clicking this button completes the revert. But you may get one of two error messages:
If you’ve turned on “Prompt me when entering a blank edit summary” in the “editing” tab of your My Preferences page (Editing), you may see a message that the edit summary is blank, even though it’s not. It’s a bug: When Wikipedia’s own software adds an automated edit summary, it sometimes doesn’t know what it just did. If you do in fact have text in the edit summary field, just click “Save page” again, and now you’re done.
If you get a message that you have an edit conflict, then someone edited and saved a change to what was the current version, before you saved. You can either repeat this four-step procedure again (more quickly, perhaps) or do a manual edit. (See Dealing with an Edit Conflict for a more detailed discussion of handling edit conflicts.)
Reverting to a prior version is appropriate only if, after looking at one or more edits, you decide that the most recent edit or edits should be reversed; for example, someone has just vandalized a page and the next-to-last version of the page is vandalism-free.
Doing this type of revert is a four-step process, starting from the history page:
Click the row for the last good version of the page.
That’s the version before the vandalism or spam occurred; the version you believe is the last good one. Click the time/date link in that row. You then see that version, with a warning near the top of the window (Figure 5-5).
Figure 5-5. You see this standard wording of the warning when you first look at an older version of a page. Wikipedia stores only the text of old versions of pages, not images in that version. At the top of the infobox, on the right, you can see “Image:Gableautopic.JPG”. If an image of that name existed in Wikipedia, you’d see it. But since the image is no longer on Wikipedia, all you see is a link to the location where the image used to be. In short, Wikipedia’s copies of old versions of pages are not photographic copies, they’re text stored in a database.
At the top of the page, click the “edit this page” tab.
Now you’ll see a second warning, just a bit more prominent, as shown in Figure 5-6.
Figure 5-6. You see this warning when you’re editing a version of a page other than the current one. Wikipedia wants to make sure you’re fully aware that if you save this page after editing, you’ll be wiping out all the edits that were made after this version was originally created, unless you manually make changes to this version that incorporate some of those edits. In this case, the last edit(s) were vandalism, not something to worry about losing.
At the bottom of the edit window, add an edit summary.
You don’t need to say much:
The most common reason for reverting is vandalism, and the most common situation with vandalism is that you’re reverting only the last edit, or only a series of edits by the same editor. If so, you need only to put rvv (which stands for revert vandalism) in the edit summary.
If you’re reverting for something other than vandalism, explain a bit; for example, rv linkspam.
If you’re reverting edits by more than one editor (for example, two different accounts vandalized the page, back to back), then mention which version you’re reverting to—for example, rvv, reverting to version of 10:05 15 May.
Click the “Save page” button.
After you’ve undone or reverted an edit (clicked the “Save page” button), it’s a good idea to glance at the page to see if reads the way you expect. If it looks the same as before you’ve edited, refresh the page in your Web browser; clicking Ctrl+R (⌘-R on a Mac) does the trick in most browsers. If the problem is gone, your revert was successful. Congratulate yourself for improving Wikipedia. If you do see some vandalism that you missed, then you can fix it with another undo, if possible, or by doing a direct edit if necessary.