Explanation

This screen appears when you try to move/rename a Page that contains an XClass used elsewhere in the wiki. 

This is what a simple user sees:

Switching to advanced user, you are allowed to choose precisely the Pages to move and those to preserve:

Such a Page might also be one of the children of the current Page. Renaming or moving it could break other Pages that depend on that XClass, which is why this action is forbidden for users who do have the deletion right but are simple users. Clicking on the "Cancel" button discards the action.

Related

• Class Page Deletion.