By default, ePublisher creates a top-level group based on the name of the project when you add your first source document to your project. There must always be at least one top-level group in Document Manager in order to add source documents to a project. You can create additional top-level groups if you want to further organize your source documents or create merged help systems, or multivolume help. For more information about creating merged help systems, see Merging Top-level Groups (Multivolume Help).