---
features:
  - |
    Ports now have a ``hints`` attribute, in which backend specific
    tuning options can be passed to Neutron. The availability of the
    ``hints`` attribute is signaled by the ``port-hints`` extension.
    The ``hints`` attribute is admin-only by default. Its value is a
    dict, keyed by mechanism driver aliases. The possible values are
    defined by the mechanism drivers. An admin user can ask for a
    hint in a port create or update request. As the name suggests a
    hint is not a demand - Neutron applies the hint when it can, but
    it is free to ignore it, when it can't.