The second style matches the brushwork of one of the passages written on the reverse side of the volume of the Engi-shiki (an ancient code of laws) owned by the Kujo family that is known to be by Kaneyuki, and for this and other reasons, even when looked at from different viewpoints, the theory that Kaneyuki was the calligrapher of the second style is all but conclusively proven.
九条家本延喜式の紙背文書（しはいもんじょ）中の兼行の筆跡との一致など、さまざまな観点から、兼行を筆者とする説はほぼ定説化している。