[Q] Differences between 'ad hoc multipoint conf' and 'multipoint conf'.

Hi, Can you tell me the differences between 'ad hoc multipoint conference' and 'multipoint conference'? According to the recommendation of H.323 V2, ad hoc multipoint conference : An Ad Hoc Multipoint conference was a point-to-point conference that had been expanded into a multipoint conference at some time during the call. multipoint conference : A Multipoint conference is a conference between three or more terminals. Any multipoint conference can begin with three or more terminals without expansion from point-to-point conference? Best wishes, soo Nada Research Co., Ltd. Korea.