The agencies have adopted a rule under which they will generally consider any group's selection rate that is less than four$-$fifths or $80$ percent of the selection rate for the group with the highest selection rate as a substantially different rate of selection. This $"4/5$ths$"$ or $"80$ percent" guideline is not intended as a legal definition but is a practical means of keeping the attention of the enforcement agencies on serious discrepancies in rates of hiring, promotion and other selection decisions.