The Glasgow Merchants' Charity Cup was a knockout football tournament open to teams from in and around Glasgow and later on in the tournament's history, teams from outwith Glasgow. Invitations were made and sent out by the Glasgow Charity Cup Committee (GCCC) at their discretion, but no criteria were ever published.
Like many domestic competitions in scottish football, it was predominantly dominated by the Old Firm of Rangers and Celtic, with 31 and 28 victories each, respectively. In the latter years of the tournament, it stopped being a knockout tournament, and became a one-off contest between a Glasgow Select and a team invited from the English League.
References
Glasgow Merchants Charity Cup Wikipedia(Text) CC BY-SA