Records which cannot be changed

• Headings on records emanating from the British Library (BL) or the English Short Title (ESTC) project should NOT not changed. Additional information and references may be added as usual.

  Errors in a heading issued by one of these bodies should be referred to the NACO Coordinator.

• Early notice records (ENRs) with fixed field code EL "o", and records containing a 667 field with a change message and fixed field code UIP "b", can be modified or upgraded only by the library which contributed the record (usually LC).

  Please report these records to the NACO coordinator.

  For more details, see the following two sections:
  Early Notice Records (ENRs)
  Change Messages