The polyhedral symbol indicates the geometrical arrangements of the coordinating atoms about the @C00930@. It consists of one or more capital italic letters derived from common geometric terms (tetrahedron, square plane, octahedron, etc.) which denote the idealised geometry of the @L03518@ around the @C01329@ centre, and an arabic numeral that is the @C01331@ of the @C00930@. The polyhedral symbol is used as an affix, enclosed in parentheses, and separated from the name by a hyphen. Examples are T-4, SP-4, TBPY-5, SPY-5, OC-6, and CU-8.