Sc Acc Arium
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
A chequered cloth resembling a chess-board which covered the table in the exchequer, and on which, when certain of the king's accounts were made up, the sums were marked and scored with counters. Hence the court of exchequer or curia scaccarii, derived its name.
3 Bl. Comm. 44.