On 10 September, a conference was held at 1 Allied Airborne Army's headquarters in England, to determine the outline plan of operation Market Garden. Present were: Brereton, Browning, Williams, Hollinghurst, Parks, Stearley, Cutler, Gavin (commander 82 Airborne Division) and MacAuliffe (deputy 101 Airborne Division). It looks like British 1 Airborne Division was not represented.
Not entirely surprising as the 10th September was the date that Operation Comet was officially cancelled to be replaced by Operation Market which was an expansion of Comet utilising the American Airborne forces to undertake tasks originality being undertaken by the 1st Airborne Division. 1st Airborne already knew the plan they just needed to explain what was now to be undertaken by the Americans