def doc_handle_sop_common(event):
    """Documentation for handlers bound to ``evt.EVT_SOP_COMMON``.

    User implementation of this event handler is required only if SOP Class
    Common Extended Negotiation is to be supported by the association.

    **Event**

    ``evt.EVT_SOP_COMMON``

    Parameters
    ----------
    event : events.Event
        The event representing an association request being received which
        contains one or more SOP Class Common Extended Negotiation items. Event
        attributes are:

        * ``assoc`` : the
          :py:class:`association <pynetdicom.association.Association>`
          that received the SOP Class Common Extended Negotiation request.
        * ``event`` : the event that occurred as ``namedtuple``.
        * ``items`` : the {*SOP Class UID* :
          :py:class:`SOP Class Common Extended Negotiation
          <pynetdicom.pdu_primitives.SOPClassCommonExtendedNegotiation>`}
          items sent by the requestor.
        * ``timestamp`` : the
          `date and time <https://docs.python.org/3/library/datetime.html#datetime-objects>`_
          that the negotiation request was processed by the ACSE.

    Returns
    -------
    dict
        The {*SOP Class UID* :
        :py:class:`SOP Class Common Extended Negotiation
        <pynetdicom.pdu_primitives.SOPClassCommonExtendedNegotiation>`} items
        accepted by the acceptor. When receiving DIMSE messages containing
        datasets corresponding to the *SOP Class UID* in an accepted item
        the corresponding Service Class will be used (if available).

    References
    ----------

    * DICOM Standard Part 7, `Annex D.3.3.6 <http://dicom.nema.org/medical/dicom/current/output/chtml/part07/sect_D.3.3.6.html>`_
    """
    pass
