Philippe started it. M'len will confirm. While the Off-world-Search Team (or OWST for those that like acronyms...) also Search Pern in their timeline, this group of riders are the only ones that are able to travel to other worlds (and times!) to find candidates for the Islan Hatching Grounds. Each of them have specially crafted harnesses inscribed with runes to allow their dragons to travel to other worlds (plane shift), shrink to firelizard, or portable, size (shrink monster), as well as the ability to hide very, very well (aka invisibility). All harnesses are runescribed by Philippe.