The conref attribute is used to reference content that can be reused. It allows reuse of DITA elements, including topic or map level elements.
The value of the conref attribute must be a URI reference to a DITA element. See URI-based (direct) addressing for details on specifying URI references to DITA elements. As with other DITA references, a conref attribute that references a resource without an ID is treated as a reference to the first topic or map in the document.
<ph conref="#topic/ph">Something</ph>the word "Something" will be replaced by the content of the referenced ph element.