NavBarItems are missing in a FormXml - Microsoft Dynamics CRM

I noticed that //FormXml/forms/systemform/form/Navigation/NavBar/NavBarItem (Navigation Bar Items) created automatically by CRM are missing in the FormXml. They appear there if you customize those navigation items, for instance: change labels or remove/add same items.

Does anyone know if there is a way to locate those "missing" navigation items without making customization to them?

I am doing a parsing of a FormXml in a Console Application (C#).

I tested it in CRM 2015 and 2016 and not sure about earlier versions if there was the same behaviour. Interesting, from where Xrm.Page.ui.navigation gets those "missing" items?