In the Catalog, you can create additional fields in the menu for all entities (Items, Sets and Articles). For example, by default, dimensions, weight, power and current are specified in the menu, but you can add your own fields — for example, "peak power", "gross weight", etc. All additional fields are created in this list. 

To create it, click the add button, enter a name and specify the units of measurement. In the future, in the Position or Article menu, on the Fields tab, you can select those of the fields you have created that should be displayed in this menu (see the Equipment menu)