leting branches:</p>

  <dl>
    <dt>Delete the branch as soon as it has been merged back to the trunk
    (prior to closing any associated Trac ticket)</dt>

    <dd>This is the tidiest approach which minimises the chances of old
    branches being left around.</dd>

    <dt>Delete the branch once a stable version of the system has been released
    which incorporates your change</dt>

    <dd>If a bug is found in your change during integration testing then you
    can prepare the fix on the original branc