An AdditionalFile element adds one HTML source file to the help system. An additional file must be in the same directory as the help file that refers to it. The required attribute Source should be set to the name of the source file, e.g. "myfile.htm". The AdditionalFile element may contain any number of SeeAlso elements. It has two optional attributes: Title and ApplyCommonFormat.
Required. The Source attribute is required. It should be set to the file name. Additional files must be in the same directory as the help file that specifies them.
The optional Title attribute controls the main title of the page. If omitted, the title element in the HTML source file will be used. This attribute is ignored if ApplyCommonFormat is false.
The optional ApplyCommonFormat attribute controls whether the contents of the HTML file are wrapped in the common page format used by the other pages in the help project. If true, then the title element and the contents of the body element will be extracted and placed into a standard page. The HTML file must be XHTML, using the schema http://www.w3.org/1999/xhtml. If false, then the file will be copied into the help project with no changes.