XRW (cross-relative work) is a skydiving discipline in which people in high performance (large) wingsuits fly with people using high performance (small) parachutes.
Finding parachute pilots capable of handing a 3:1 wing-loading as well as wingsuit pilots who are able to squeeze enough performance out of their suit is challenging, and as such there are only a small number of pilots who have successfully docked an XRW formation. As a parachute's lines can act like cheese wire at speeds of over 170kph, no-fly zones will generally be established by the pilots.
Because both the canopy and the wingsuit can steer violently with something as small as a glance to the left or right, XRW takes a lot of team preparation and practice.