Regarding my comment "N.B. is it banned titles or protected titles?" ... a bit of an opinion:
From a XenForo 2 only perspective, this could be renamed to "Disallowed titles" or "Disallowed page titles" to match XF's "Disallowed custom titles" option (in "User registration" options group). It would then avoid the word protected which VW already associates with restricted editing on pages.