Manual:$wgDefaultSkin/zh

细节
此设置定义缺省皮肤，需确认皮肤名称首字母小写（例如：‘的MonoBook’而不是‘MonoBook’）

注意，此设置仅限“默认”皮肤. 此皮肤仅用于未登录用户或者未更改默认设置（例如在用户设置中的设置）皮肤的登录用户.

去除皮肤时更改用户首选项
In versions up to at most 1.11, upon registration the value of  was copied to the user preferences; thus setting $wgDefaultSkin to another skin would not have had any effect on registered users, even if they never changed their preferences. And it did not have an effect on registered users, who did change the skin to use.

When you remove a skin from the list of skins to choose from, use the maintenance script Manual:UserOptions.php to make sure that this skin is also not chosen by any user:

选择Monobook、Vector会改变所有用户的皮肤.

启用皮肤
Several skins are included with the MediaWiki installer tarball (the table below details the versions they were/are available with). You can find more skins in Category:All skins.

The first column gives the ID which should be used to configure this setting, the second gives the name as it appears within the MediaWiki interface and the third indicates the versions of MediaWiki that this skin is available for: