The list came to be called Omagaki because a blank space (between lines) was set as large, in advance, in order to enter Ikai (Court rank) and Shisei (name) of candidates (Jugan (completion of document only with information on Ikai or government post by entering names) when listing names of vacant government posts in order to create the original copy.
原紙を作成のために欠員の官職名を列記する際に予め候補者の位階氏姓名を記入する（入眼（じゅがん））を行うための空白（間）が大きく開けられていたことから、「大間書」と呼ばれた。