An included file type is an HTML snippet. It is a fragment of HTML that will be included in another file.
Included files are editable in the WebEdit WYSIWYG considering that:
1. the HTML code it contains is complete - no open tags;
2. it only contains elements you would normally put inside the BODY.
Included files are editable in text mode even if:
1. the HTML code it contains not is complete;
2. it contains HEAD elements.
