Library /sys$common/syshlp/basichelp.hlb Run time errors, TAPNOTANS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Tape not ANSI labeled (ERR=146)

  The program attempts to access a file-structured magtape that does not
  have  an  ANSI  label.   Determine the magtape's format by mounting it
  with the /FOREIGN qualifier and using the DCL DUMP command.   You  can
  then access it as a non-file-structured magtape.