Library /sys$common/syshlp/basichelp.hlb Conventions, File specification  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  A full file specification has the form:

     node::device:[directory]filename.filetype;version

  This is an example of a complete file specification:

     OAK::LIMB4:[TWIG2]LEAF1.BAS

  Often  the  full  file  name  is  the  only  required  part  of  a  file
  specification.   If you omit any other part, your current default values
  are used.  Under certain circumstances, you can assign a logical name to
  access files not in your current default directory.