https://www.debian.org/doc/debian-policy/ch-source.html#debian-changelog-debian-changelog

Series of Changes

package (version) distribution(s); urgency=urgency
  [optional blank line(s), stripped]
  * change details
  more change details
  [blank line(s), included in output of dpkg-parsechangelog]
  * even more change details
  [optional blank line(s), stripped]
-- maintainer name <email address>[two spaces]  date