Manual:$wgCategoryPrefixedDefaultSortkey/ja

詳細
Switch which determines if the namespace name should be included in (true, default) or removed from (false) the default category sortkey.


 * Set this to false in order to have a useful alphabetical default sort of non-ns0-pages in categories.
 * You have to run maintenance/ after changing this.

1.17 以降、これは常に false です.