Chunking DITA Topics
By default, when a DITA map is published to an online format, each topic becomes a separate page in the output. In some cases, you may want to combine multiple source topics into one output page. For instance, you may want to combine several types of information into a single page, or you may have chosen to create many small DITA topics for reuse purposes but feel they are too small to be useful to a reader by themselves. This is referred to as chunking.
To chunk DITA topics, you set the chunking attribute on the topicref that
            contains the sub-topics in a DITA map. There are several values that you can set on
            the
            chunking attribute (for example, by-topic or to-content).
            See the DITA documentation for full details. To achieve the
            effects you want in your topics and table of contents, you may also need to set the
            toc and collection-type attributes on the sub-topics or
            container topic to suitable values. See the DITA documentation for details. 
         
You can set the collection-type attribute on your topics using the
            Edit Properties action in the DITA Maps
               Manager. To set the toc and chunk attributes,
            you must open the map file in the editor and add or edit the attributes directly (double-click
            the map icon  in the
            DITA Maps Manager to open the map in the editor).
 in the
            DITA Maps Manager to open the map in the editor).
         
