《太平广记·卷二百零九·书四》
他们的草书真迹，又令褚遂良用真书体写成小字，帖纸拓影，附在后面。
其草迹，又令褚遂良真书小字，帖纸影之。
 According to him, all genuine cursive scripts should be copied by Chu Suiliang in small regular characters, and then attached to the back of the rubbings.