[1.3.X] Fixed #17618 - Documented that variable names in template must not start with an underscore; thanks guillemette and krzysiumed.
[1.3.X] Fixed #17618 - Documented that variable names in template must not start with an underscore; thanks guillemette and krzysiumed.

Backport of r17504 from trunk.

git-svn-id: 6bee183d120e8e569924b918ee6c564bbb314a32@17505 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django-nonrel/django-nonrel,django-nonrel/django-nonrel,django-nonrel/django-nonrel