This should be a widget area (widget_area area=extra_area area_style=top) :

---

[ widget_area area=x1 area_style=footer ]

[widget_area] - Area per-page-x1 not defined.

---

[ widget_area area=x1 area_style=primary ]

[widget_area] - Area per-page-x1 not defined.

---

[ widget_area area=x1 area_style=top ]

[widget_area] - Area per-page-x1 not defined.

---

[ widget_area area=x1 area_style=bottom ]

[widget_area] - Area per-page-x1 not defined.

---

…