/sys$common/syshlp/helplib.hlb LSEDIT, Command Qualifiers, /INITIALIZATION  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /INITIALIZATION=file-spec
  /NOINITIALIZATION (D)

  Specifies the name of a file containing a sequence of LSE  commands  to
  be  executed  as  part  of  LSE  startup.   This  file usually contains
  occurrences of the DEFINE KEY and DEFINE commands.

  The  logical  name  LSE$INITIALIZATION  is  an   alternative   to   the
  /INITIALIZATION  qualifier.  If /INITIALIZATION or /NOINITIALIZATION is
  not  used,  LSE  will   attempt   to   translate   the   logical   name
  LSE$INITIALIZATION.   If the logical name has a translation, that value
  is used in the same way as the /INITIALIZATION qualifier value.

  If the initialization file specified does not contain a file type,  the
  file  type  applied  depends  upon  the  system-defined default command
  language.  If the default command language is VMSLSE, ".LSE" is applied
  as  always;  if  the  default  command language is Portable, ".PLSE" is
  applied.