Complex sentence: A method of informing the opponents that partner's bid carries a meaning that they might not expect; alerts are regulated by sponsoring organizations such as the ACBL and the EBU, and by individual clubs or organisers of events.
Split into simpler sentences: A method of informing the opponents that partner's bid carries a meaning that they might not expect. Rules on which bids must or must not be alerted are determined by sponsoring organizations such as the ACBL and the EBU, and by individual clubs or organisers of events.