By specifying a CMS ACL on the CMS library or the library
  history, you can restrict users from certain types of
  access to the library or the library history.

  You can restrict users from the following types of access
  to the library:  MODIFY, REPAIR, VERIFY.

  You can restrict users from the following types of access
  to the library history:  DELETE, REMARK.

  See the "Guide to DIGITAL Code Management System for OpenVMS
  Systems" for a more detailed explanation of using ACLs on
  the library or library history.