Users cannot see it by default. In order to see it on pages where it has been placed, users must click an option in Special:Preferences.
In general, categories should not be hidden. However, in the case of categories which are created solely for use with advanced coding functions like DPL or SMW, or when they have been created in order to facilitate the Game of Rassilon, it can be useful to hide them.
Please do not remove this message from this page without discussion at the Panopticon.
此分類為MediaWiki軟體自動生成的「隱藏分類」。它包含使用內部魔術連結系統連結到ISBN的頁面。