An include file is either an image file or an HTML file. You can have multiple include files in a single theme. The result of the inclusion is the *.theme files that are used to build the help target. For an HTML include file, only its body, the content that is normally placed inside the <BODY> tags should be present in the file. The <BODY> tags themselves and everything outside (<HTML> tags, <HEAD> tags, etc.) should be removed from the include file. Doc-To-Help does not verify this or change the included content. The inclusion is performed literally, the whole contents of the file is included.