You use the Volume entity to publish a document that contains instance descriptions.
For clarity purposes, a Volume can contain titles on various hierarchical levels.
It calls instance descriptions such as the -D Lines, -CE Lines, -G Lines, or Keywords.
The instances are explicitly called in the Volume or are dynamically retrieved by requests according to selection criteria.
After it is described, a Volume must be generated from the Design Explorer view to be transformed into a document that can be published. The generation produces a file with an XML or an HTML format.