I wasn’t born yesterday. I’ve used a computer since I was a fetus. I started learning JavaScript, CSS, and HTML when I was 3 years old, Python when I was 6, C# when I was 9, and Swift when I was 11. I checked all the links on the first page of the Google search result page which you provided in your post.

Help:System messages doesn’t say anything about changing edit summaries, either, and I don’t want to go through the whole Special:AllMessages list.

MediaWiki:Undo-summary is the mediawiki page you're looking for. Unfortunately, it hasn't been whitelisted yet.

Thanks. Too bad no one can edit it, though. Why isn’t it whitelisted, and when will it be?

That is because there had been a security incident on Wikia some time ago, and because MediaWiki messages are used so abundantly, (imagine someone injecting malicious code in thr message above preventing them from reverting) Wikia has limited access to them. You can ask Staff to edit them though, and new whitelisted messages are announced on Technical Update blogs on Community Central.

I’ll ask contact staff, if that’ll help.

People can inject malicious code anywhere, though, can’t they? They can also hide features which shouldn’t be hidden. That’s why code that breaks the ToU will get removed.

Thank you for your help, though. Your help was a lot better than the guessing game Dessamator played with me previously, which led me nowhere (no offence).

Great, then you don't need to file any more script suggestions since you claim to know javascript, CSS, html and this is such a trivial script.

Also, the help page lists everything Mainframe98 said, perhaps it should be read more closely.

This is a developers wiki, not the spoonfeeding wiki as far as I know.

I do know JavaScript, CSS, HTML, and more programming languages, indeed. In fact, Donald Trump, a close friend of me, taught me C++ when I was 13 years old. Also, you’re right. Because I started learning so many programming languages, I also know about every single MediaWiki page and never need to ask about Wikia features ever again, because knowledge of JavaScript, CSS, HTML, and Python equals me knowing everything.

Anyway, Help:System messages doesn’t list anything which Mainframe98 said. It says that some MediaWiki pages aren’t whitelisted, but that’s it.

Trolling on Dev Wiki is not helpful and will likely get people to ignore you.

I’m not trolling. I’m inserting sarcastic jokes in my otherwise useful posts. I was making a joke, someone presumably took it seriously, and I was expanding on my joke as a response.

By the way, I just realized that the MediaWiki thing won’t fully satisfy my needs, as I want to use “Undid” whenever I undo edits, as I find it much more logical, but wikis rarely have their MediaWiki:Undo-summary edited to say “Undid” instead, especially considering how it’s not whitelisted. I’d find a script which changes “Undo” to “Undid” on every wiki (just for personal use, of course) very useful.

As it happens, asking for scripts then being "sarcastic" when the answer is not to your liking is not going to bring about the script. Nor is it likely to make anyone want to help you in the future. At the same time, suggesting the use of system messages as a solution to a personal preference across multiple wikis via the condescending manner of a vague google search (which really wasn't obvious) is unlikely to help the discussion either.

Therefore, I'm closing this in the interests of preventing this getting any more fractious. However, as the script is so trivial, here it is:

$(function () {
    var $input = $('#wpSummary'),
        summary = $input.val();
        
    if (summary.indexOf('Undo') === 0) {
        $input.val(summary.replace('Undo', 'Undid'));
    }
});