International
Tables for Crystallography Volume A Spacegroup symmetry Edited by M. I. Aroyo © International Union of Crystallography 2016 
International Tables for Crystallography (2016). Vol. A, ch. 2.1, p. 146

^{†}The symbols are given at the upper left corner of the spacegroup diagrams. A fraction h attached to a symbol indicates two symmetry planes with `heights' h and above the plane of projection; e.g. stands for and . No fraction means and (cf. Section 2.1.3.6).
^{‡}The graphical symbols of the `e'glide planes are applied to the diagrams of seven orthorhombic A, C and Fcentred space groups, five tetragonal Icentred space groups, and five cubic F and Icentred space groups. ^{§}Glide planes d occur only in orthorhombic F space groups, in tetragonal I space groups, and in cubic I and F space groups. They always occur in pairs with alternating glide vectors, for instance and . The second power of a glide reflection d is a centring vector. 