Historical Records
Huyan in Han Dynasty Xiongnu Records
The History of the Former Han records “呼衍氏”; Yan Shigu’s annotation says it was the Xianbei surname 呼延 of his time.
Textual Attestation and Orthographic Boundary
The source records the form “呼衍氏” from the Former Han History, and additionally quotes Yan Shigu’s note as saying, “即今鮮卑姓呼延者是也.” This is a quotation of the classical text and commentary by the supplied source; “呼衍” and “呼延” should be kept distinct and should not be treated as the same written form or merged into one surname dataset solely on this basis.