In #17680, looking at Firefox's long rectangular URL entry area, the URL is
http://radioscanningtw.jidanni.org/index.php?title=特殊%3A所有页面&from=保全&to=高雄縣警察局鳳山分局&namespace=1
Note the 页 character, it is zh-tw non-simplified Chinese.
OK, now visit Special:Categories:
http://radioscanningtw.jidanni.org/index.php?title=特殊:页面分类
For this string now we get zh-cn 页 simplified!
Version: 1.14.x
Severity: trivial
URL: http://radioscanningtw.jidanni.org/index.php?title=特殊:页面分类