In a demand-bidding scenario for DR, a standing bid is typically set by the VEN (e.g., DR participant) within a particular DR service provider program with option to adjust or cancel the bid. If the bid is not adjusted/canceled, the standing bid will be submitted at the end of the bid period. This is also sometimes called (in Auto-DR terminology) as "auto bid, auto shed," meaning you set the bid one time (standing bid) and it will be submitted without any actions from the participant.
Page 83 of OpenADR 1.0 specifications state the following on standing bid – "A standing bid is a bid that will be submitted by the DRAS for a participant if no other bid is submitted by the participant. The ability to automatically submit standing bids increases the level of participation in programs that require bidding. In some case the utility's or ISO's IT infrastructure will already support the notion of standing bids and in those cases it is not necessary for the DRAS to provide this functionality. In fact there may be scenarios where there are programs that require bidding, but all the bidding is handled by a different system than the DRAS, including the handling of standing bids. In this case, from the DRAS point of view, the program will not require bidding and all the DR events are simply issued by the utility or ISO as in the case of programs with no bidding. The utility or ISO will simply handle all the bidding as they normally would and use the DRAS to issue the DR events."
I think this should be expressed in the language of the EMIX Option, i.e., a business schedule during which execution calls can be mase with a warranted response time.