An additional guard, member of longpoint family. It is similar to hanging guards from later fencing systems - sword points down and a bit back, shield is retreacted in order to cover the body while closing in. You are expected to use it in order to close the distance while retaining the bind.
This position is used to close in from contact distance (where you can reach the opponent with the sword without stepping) into grappling distance (where you can reach your opponent with hands without stepping). So priest's special longpoint may be considered a gateway to one of the two grappling plays from the manuscript (frontal arms grab and back arms grab). I.33 considers this a siege, even though it is not happening from out of measure but step closer. You perform this close in (with a switch into priest's special longpoint) from binding below and on the left.