The IUPAC nomenclature rules for coordination compounds are: (1) Cation is named before anion; (2) Ligands are named alphabetically before the central metal; (3) Anionic ligands end in '-o' (chlorido), while neutral ligands use common names (aqua for H₂O, ammine for NH₃, carbonyl for CO); (4) Prefixes di-, tri-, tetra- indicate number of ligands, but bis-, tris-, tetrakis are used when ligand names contain numerical prefixes like 'ethane-1,2-diamine'; (5) For anionic complexes, metal names end in '-ate' (nickelate); (6) Oxidation state is indicated in Roman numerals in parentheses after the metal name.