Javadocs can be created for CM source code. They are designed to be integrated into the product's Javadocs.
The product's Javadocs are only delivered for objects or supporting objects that are intended to be referenced by CM code. For instance, only the domain and api packages are included, and some of the files created by the artifact generator are not delivered since they have no practical relevance to CM code. These files have been deliberately and explicitly omitted when creating the product's Javadocs.
Refer to Creating Javadocs for CM Source Code for more information.