========================================================================
Top-level label
========================================================================

label: node {};

---

(document
    (labeled_item
        label: (identifier)
        item: (node name: (identifier))
    )
)

========================================================================
Labeled child node
========================================================================

/ {
    label: property-name@deadbeef {};
};

---

(document
    (node
        name: (identifier)
        (labeled_item
            label: (identifier)
            item: (node
                name: (identifier)
                address: (unit_address)
            )
        )
    )
)