Under the most recent treaty, Mexican Class A stations which previously operated with 50 kW or less (but a minimum of 10 kW nights) may increase power to 100 kW days while retaining their 10 kW night operation. This created some anomalies where stations licensed for 10 kW during all hours could increase power to 100 kW days and 10 kW nights, unless a directional antenna system was installed for nights, in which case the maximum night power was 50 kW. Additionally, one Class B station which had been operating non-directionally with 100 kW days and 50 kW nights was required to reduce power to 50 kW during all hours.