Eastern Han scholar Zheng Xuan as "to enquire into the correctness" of a proposed activity.

The names of the hexagrams are usually words that appear in their respective line statements, but in five cases (2, 9, 26, 61, and 63) an unrelated character of unclear purpose appears. The hexagram names could have been chosen arbitrarily from the line statements, but it is also possible that the line statements were derived from the hexagram names. The line statements, which make up most of the book, are exceedingly