You can conceptually think of element, group, and class
  lists as generic objects representing, respectively,
  all the elements, groups, and classes that already exist,
  or have yet to be created in the CMS library.

  You use the object lists with access control lists (ACLs)
  to grant or deny access to objects already created in the
  library, or objects that will be created in the library.

  See the "Guide to DIGITAL Code Management System for
  OpenVMS Systems" for a more detailed explanation of object
  lists.