The central dialog Class systems: Edit... [Class systems: edit...] dialog in the Extras menu via the menu command Class systems: Edit... [Class systems: edit...] menu command.

Menu: Extras > Class systems: Edit... [Class systems: edit...]

Dialog "Class systems: Edit... [Class systems: edit...]"

If you want to edit a class system, select the appropriate one from the Class system list box.

If If you want to create a class system from scratch, the selection in the list field irrelevant and you simply click on the button New class system create... [Create new class system...] (see Section 5.12.4.3, “ Create class system / Change current class system... (Basic settings) ”).