<p>That looks to be using this script which can’t be imported sitewide </p><p>Instead you can add it to either global.js or common.js. </p><p>Note: However, if you want to have something that can be imported sitewide to purge pages, this script is a good option. </p>

<p>It's not really a button, but it should work for UCP. </p>

<p>Actually, appending more options to the edit dropdown is one of the few article header customizations that wikis are allowed to do. </p>

<p>I think the problem comes when you try to remove stuff, not add. </p>

<p>Maybe staff ordered this option specifically to not be added sitewide, because users may overuse it and put strain on the servers. </p>

<p>I highly doubt that... more likely they made the not unreasonable assumption that purge is not someting that should be regularly needed. With the coming of UCP they were wrong, but they are often wrong. </p>

<p>HumansCanWinElves, it looks like the notice was added by Plover-Y who somehow had staff status for 1 week? I am not sure what that is about but I wouldn't consider the notice to mean staff require it to be used in personal JS only. Do you have some other source of info for that claim? </p>

<p>I have no source, and actually I see it was added by "Marcus Tiberius" which have no notable contributions. </p><p>Could it just be a mistake that got unnoticed for years? </p>

<p>However, I discovered that it the "personal use only" template was restored to the page in October 2018 by Dorumin </p><p>Source this edit revision. </p>