Yo, Cho (from Ritsuryo system), and Suiko (government loans), which were formerly a per-capita tax, became a property tax (including parts of Zoyo, or irregular corvee) like So.
本来は人頭税であった庸・調(律令制)・出挙が、租と同じように地税化（雑徭の一部を含む）していった。