Superscript is an editorial introduction found in the beginning of a book of scripture and is used regularly throughout the Old Testament. Here is an example:

1 The words of Jeremiah the son of Hilkiah, of the priests that were in Anathoth in the land of Benjamin:
2 To whom the word of the Lord came in the days of Josiah the son of Amon king of Judah, in the thirteenth year of his reign.
3 It came also in the days of Jehoiakim the son of Josiah king of Judah, unto the end of the eleventh year of Zedekiah the son of Josiah king of Judah, unto the carrying away of Jerusalem captive in the fifth month. (Jeremiah 1)

The Book of Mormon contains similar editorial introductions:

An account of Lehi and his wife Sariah and his four sons, being called, (beginning at the eldest) Laman, Lemuel, Sam, and Nephi. The Lord warns Lehi to depart out of the land of Jerusalem, because he prophesieth unto the people concerning their iniquity and they seek to destroy his life. He taketh three days’ journey into the wilderness with his family. Nephi taketh his brethren and returneth to the land of Jerusalem after the record of the Jews. The account of their sufferings. They take the daughters of Ishmael to wife. They take their families and depart into the wilderness. Their sufferings and afflictions in the wilderness. The course of their travels. They come to the large waters. Nephi’s brethren rebel against him. He confoundeth them, and buildeth a ship. They call the name of the place Bountiful. They cross the large waters into the promised land, and so forth. This is according to the account of Nephi; or in other words, I, Nephi, wrote this record. (1 Nephi 1)