All records have a few system fields available in addition to the fields defined by the data model. These fields are always there and control internal behavior in Lektor. They are prefixed by an underscore to separate them from the fields a model defines.
Many system fields are hidden from the admin panel but some can be changed
_hidden, and a few others).
Controls if this page is picked up by collection queries by default.
A globally unique ID of the page.
Selects the template for the page.