Fill in the Library Specification(s) field with one or
  more library specifications.

  To specify a library search list, enter the library
  specifications on one line, separating each specification
  with a comma.  When you double click on the search list
  from the Known Libraries box in the Open Library dialog
  box, CMS opens the entire search list.

  To specify individual library names, enter a single
  library specification, then choose the Add button.  Do
  this for each library specification.  Each time you
  choose the Add button, CMS adds each name in list form
  to the Known Libraries box.  You can specify up to ten
  libraries in the Known Libraries field.