Green–Davies–Mingos rules
In organometallic chemistry, the Green–Davies–Mingos rules predict the regiochemistry for nucleophilic addition to 18-electron metal complexes containing multiple unsaturated ligands. The rules were published in 1978 by organometallic chemists Stephen G. Davies, Malcolm Green, and Michael Mingos.
Source: Wikipedia — Green–Davies–Mingos rules (CC BY-SA 4.0)