Under the Machinery Directive 2006/42/EC when partly completed machinery is first placed on the market it will not be CE marked, but it must be accompanied by a Declaration of Incorporation instead of a Declaration of Conformity.
This particularly applies to machinery that is to be incorporated into existing equipment and cannot operate independently. The Recipient of any machinery that is accompanied by a Declaration of Incorporation is responsible for ensuring that the finished Assembly conforms to the relevant Directives, generating a Declaration of Conformity, and affixing a CE mark before the Assembly is brought into use.
In certain cases, when rebuilding an existing Client machine, R&R have provided a Declaration of Incorporation so that the Client is able to integrate the machine into a final assembly or production line.