Personally I think to add an icon (using an icon font or possibly a data uri) is...

wubbfindel on Feb 13, 2013 | parent | context | favorite | on: Markdown.css – make HTML look like plain-text

Personally I think to add an icon (using an icon font or possibly a data uri) is a great (and proper) use-case for displaying content with either the :before or :after selector.