minor_changes:
  - "slack - add option ``prepend_hash`` which allows to control whether a ``#`` is prepended to ``channel_id``. The current behavior (value ``auto``) is to prepend ``#`` unless some specific prefixes are found. That list of prefixes is incomplete, and there does not seem to exist a documented condition on when exactly ``#`` must not be prepended. We recommend to explicitly set ``prepend_hash=always`` or ``prepend_hash=never`` to avoid any ambiguity (https://github.com/ansible-collections/community.general/pull/5629)."