A file conversion system includes a filter and conversion tool and an Hypertext Markup Language (HTML) to Extensible Hypertext Markup Language (XHTML) tool. The filter and conversion tool reads a first file comprises a first digital content item and a corresponding first indication of style to be applied to the first digital content item and a second digital content item and a corresponding second indication of style to be applied to the second digital content item. The filter and conversion tool modifies the first file to remove the first digital content item from the first file and converts the modified first file to a second file comprising the second digital content item and a HTML tag based on the second style indication of the first file. The HTML to XHTML tool converts the second file to a third file comprising XHTML tags.