Original Manuscript of the Book of Mormon shows "second" was inserted at the beginning of "the Book of <second> Nephi."
Original Manuscript of the Book of Mormon, circa 12 April 1828–circa 1 July 1829, p. 46, The Joseph Smith Papers, accessed July 20, 2026
The Book of ^<second> Nephi
The text in angled brackets was inserted above the line in darker ink.