.. rubric:: Legend for changelogs

- |MajorFeature| something big that you couldn't do before.
- |Feature| something that you couldn't do before.
- |Efficiency| an existing feature now may not require as much computation or
  memory.
- |Enhancement| a miscellaneous minor improvement.
- |Fix| something that previously didn't work as documented -- or according
  to reasonable expectations -- should now work.
- |API| you will need to change your code to have the same effect in the
  future; or a feature will be removed in the future.