Choose the Verify... menu item to instruct CMS to
  perform a series of consistency checks on your CMS
  library. CMS verifies libraries to confirm that the
  library structure and library files are in a valid form.

  By default, CMS verifies all the elements in each library
  in the library search list.  To specify that CMS verify
  only the first occurrence of each element in the search
  list, use the Occlude option.

  When you choose Verify..., a dialog box appears, enabling
  you to specify options for the library to be verified.