* Orbifold signature: 
* Coxeter notation (rectangular): [((&infin;,2),(&infin;,2))]
* Coxeter notation (square): [4,4]
* Lattice: rectangular
* Point group: D
* The group pgg contains two rotation centres of order two (180°), and glide reflections in two perpendicular directions. The centres of rotation are not located on the glide reflection axes. There are no reflections.
;Examples of group pgg