Suggest improvement to [[MediaWiki:Showdiff/en]]
This message should be "Show differences", since the current message "Show changes", look very alike to the near button "Publish changes" or "Save changes", which can easily cause mistake: clicking the wrong button.
Apparently a Phabricator task would be necessary to make the change, if a consensus can even be reached about this, since English messages cannot be translated here, as alluded to ("one of the developers at the project concerned will change the message") at FAQ#Improving the English source message. I don't think this is actually the best place to discuss such a change. Try Translating talk:MediaWiki instead.