Some documentation formats such as HTML and Word documents (Doc, DocX and RTF files) can be split into multiple topics. When selecting one of the supported file in the "File" / "Import" dialog, the "Try to split document into multiple topics" checkbox will be enabled. When checked, it is possible to split documents by:

Note: Only checked levels will be imported as topics into HelpNDoc. Other levels will be placed as content within higher level topics.