old_contents: """
  Default settings for the ``mezzanine.blog`` app. Each of these can be
  overridden in your project's settings module, just like regular
  Django settings. The ``editable`` argument for each controls whether
  the setting is editable via Django's admin.
  
  Thought should be given to how a setting is actually used before
  making it editable, as it may be inappropriate - for example settings
  that are only read during startup shouldn't be editable, since changing
  them would require an application reload.
  """
  
  from django.utils.translation import ugettext_lazy as _
  
  from mezzanine.conf import register_setting
  
  
  register_setting(
      name="BLOG_BITLY_USER",
      label=_("bit.ly username"),
      description=_("Username for http://bit.ly URL shortening service."),
      editable=True,
      default="",
  )
  
  register_setting(
      name="BLOG_BITLY_KEY",
      label=_("bit.ly key"),
      description=_("Key for http://bit.ly URL shortening service."),
      editable=True,
      default="",
  )
  
  register_setting(
      name="BLOG_USE_FEATURED_IMAGE",
      description=_("Enable featured images in blog posts"),
      editable=False,
      default=False,
  )
  
  register_setting(
      name="BLOG_URLS_USE_DATE",
      label=_("Use date URLs"),
      description=_("If ``True``, URLs for blog post include the month and "
          "year. Eg: /blog/yyyy/mm/slug/"),
      editable=False,
      default=False,
  )
  
  register_setting(
      name="BLOG_POST_PER_PAGE",
      label=_("Blog posts per page"),
      description=_("Number of blog posts shown on a blog listing page."),
      editable=True,
      default=5,
  )
  
  register_setting(
      name="BLOG_RSS_LIMIT",
      label=_("Blog posts RSS limit"),
      description=_("Number of most recent blog posts shown in the RSS feed."),
      editable=True,
      default=20,
  )
  
  register_setting(
      name="BLOG_SLUG",
      description=_("Slug of the page object for the blog."),
      editable=False,
      default="blog",
  )
  
new_contents: """
  Default settings for the ``mezzanine.blog`` app. Each of these can be
  overridden in your project's settings module, just like regular
  Django settings. The ``editable`` argument for each controls whether
  the setting is editable via Django's admin.
  
  Thought should be given to how a setting is actually used before
  making it editable, as it may be inappropriate - for example settings
  that are only read during startup shouldn't be editable, since changing
  them would require an application reload.
  """
  
  from django.utils.translation import ugettext_lazy as _
  
  from mezzanine.conf import register_setting
  
  
  register_setting(
      name="BLOG_BITLY_USER",
      label=_("bit.ly username"),
      description=_("Username for http://bit.ly URL shortening service."),
      editable=True,
      default="",
  )
  
  register_setting(
      name="BLOG_BITLY_KEY",
      label=_("bit.ly key"),
      description=_("Key for http://bit.ly URL shortening service."),
      editable=True,
      default="",
  )
  
  register_setting(
      name="BLOG_USE_FEATURED_IMAGE",
      description=_("Enable featured images in blog posts"),
      editable=False,
      default=False,
  )
  
  register_setting(
      name="BLOG_URLS_USE_DATE",
      label=_("Use date URLs"),
      description=_("If ``True``, URLs for blog post include the month and "
          "year. Eg: /blog/yyyy/mm/slug/"),
      editable=False,
      default=False,
  )
  
  register_setting(
      name="BLOG_POST_PER_PAGE",
      label=_("Blog posts per page"),
      description=_("Number of blog posts shown on a blog listing page."),
      editable=True,
      default=5,
  )
  
  register_setting(
      name="BLOG_RSS_LIMIT",
      label=_("Blog posts RSS limit"),
      description=_("Number of most recent blog posts shown in the RSS feed. "
          "Set to ``None`` to display all blog posts in the RSS feed."),
      editable=True,
      default=20,
  )
  
  register_setting(
      name="BLOG_SLUG",
      description=_("Slug of the page object for the blog."),
      editable=False,
      default="blog",
  )
  
subject: Update BLOG_RSS_LIMIT setting description to describe setting it to None for no limit.