Every block element in DocBook that is the target of a cross reference or hypertext link must have an ID attribute. You can have DITA2Go automatically assign an ID to each block element derived from a paragraph (or to an interpolated parent of such a block element). You can also use PI markers to assign IDs to specific block elements, or to override a DITA2Go-assigned ID.
§26.4.4.1 Understanding how DITA2Go creates ID attribute values
§26.4.4.2 Providing IDs for block elements
§26.4.4.3 Providing IDs for interpolated parents of block elements
§26.4.4.4 Specifying an ID for an individual block element or parent