.. _TERM_0004:

TERM_0004 — isbn-format-invalid
===============================

**Error Code**: TERM_0004

**Message**: ``Invalid ISBN format.``

**Problematic query**:

.. code-block:: text

    IS=978-3-16-148410-0

**Recommended query**:

.. code-block:: text

    IS=978-3-16-148410-0

**Typical fix**: Use a valid ISBN-10 or ISBN-13 format (e.g., 10 or 13 digits, optionally with hyphens in correct positions).

**Back to**: :ref:`lint`