A number of sections are delivered out of the box, based on standard interfaces and purposes. To see the base form sections in your system, click Find > Administration > Form Section. You can view details about the delivered sections by right-clicking a section, and clicking Details.
If a new class is created for an owned item and then a form is generated, there will be no ownership section on the form. This is because it is not known if ownership is wanted by the owner and or owning group. Also, it is not known if it is required, so it is up to the administrator to add these standard sections as needed.