File: //usr/lib/python3/dist-packages/trac/ticket/templates/ticket_notify_email.txt
${ticket_body_hdr}
${ticket_props}
# if ticket.new:
${ticket.description}
# else:
#   if changes_body:
${_('Changes (by %(author)s):', author=change.author)}
${changes_body}
#   endif
#   if changes_descr:
#     if not changes_body and not change.comment and change.author:
${_('Description changed by %(author)s:', author=change.author)}
#     endif
${changes_descr}
--
#   endif
#   if change.comment:
${_('Comment:') if changes_body else
  _('Comment (by %(author)s):', author=change.author)}
${change.comment}
#   endif
# endif
${'-- '}
${_('Ticket URL: <%(link)s>', link=ticket.link)}
${project.name} <${project.url or abs_href()}>
${project.descr}