The usual method of using content references pulls element content from a source element and inserts it in the current topic. DITA 1.2 introduced an alternative method of content referencing, allowing element content to be pushed, or injected, from a source topic to another topic without any special coding in the topic where the content will be re-used. This technique is known as a content reference push mechanism (conref push).
The conref push mechanism requires elements in the target topic (the topic where the content is to be pushed) to have id elements, as the push mechanism inserts elements before or after a named element, or replaces the named element. Assuming the source topic is included in the DITA map, the conref push will be processed during publishing stage for the DITA map.
On the technical side, the value of the conaction attribute in the current element will be set to pushreplace and the conref or conkeyref attribute will be set to the specified reference.
On the technical side, the value of the conaction attribute in the current element will be set to pushbefore. Another element with the same name and class as the target element will be inserted in the document after the current element. The new element will have the conaction attribute set to mark and the conref or conkeyref attribute will be set to the specified reference.
On the technical side, the value of the conaction attribute in the current element will be set to pushafter. Another element with the same name and class as the target element will be inserted in the document before the current element. The new element will have the conaction attribute set to mark and the conref or conkeyref attribute will be set to the specified reference.
You can also use the Preview panel to view the content that will be pushed and the Source panel to see the XML code for the content to be pushed. After you click OK, the conref push mechanism is inserted in the current document. The changes in the target resource will be processed when you transform the DITA map.