[1] The official definition of the Welterweight weight class in Mexico is between 70 kg (150 lb) and 78 kg (172 lb), but the weight limits are not always strictly adhered to.

[3] The first Welterweight champion was Dr. Cerebro, winning the title on March 1, 1998, in a tournament final against Shiima Nobunaga.

[1] Dr. Cerebro Jr. is the current champion, having defeated Puma de Oro and then-champion Tonali for the title on January 1, 2024.

[b] On occasion the promotion declares a championship vacant, which means there is no champion at that point in time.

This can either be due to a storyline,[c] or real life issues such as a champion suffering an injury being unable to defend the championship,[d] or leaving the company.