A subquest is part of another quest which upon completion earns additional rewards as well as another quest point. In contrast, a miniquest does not earn quest points. Subquests are shorter than normal quests and usually take less time and require less items, although they may have an additional skill requirement. Currently, only a few subquests exist, most of which make up the master-level Recipe for Disaster quest, which is almost entirely composed of subquests.
Here is a list of all subquests: