This is the same treatment with the changes made in the Imperial Court of Emperor Tenmu in which the Kabane of the clan corresponding to the head of clan was changed into Muraji as the preliminary step before to get to Yakusa no Kabane (eight official titles conferred upon nobles by Emperor Tenmu in 684); Emperor Tenmu made this Muraji (above the rank of Shokini) a base point and changed into four hereditary titles of above Imiki.
これは、天武朝において氏上に相当する氏が八色の姓に改姓する前段階として、まず連への改姓が行われ、この連＝小錦位以上を基点として、忌寸以上の四つの姓へ改められたことと同様の対応である。