Library /sys$common/syshlp/teco.hlb TECO, Memory  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  TECO automatically remembers the file being edited.  The file's
  name is stored in a process logical called TEC$MEMORY.  If you
  invoke TECO without specifying a file-spec, TECO will read its
  memory logical and re-edit the last edited file.  TECO's memory
  feature is completely inhibited by the /NOMEMORY qualifier.