In a couple of places, twentieth-century LDS editions have capitalized generic nouns that refer to Christ. Here in 1 Nephi 1:9 the 1981 edition capitalized one since it refers to Christ coming down upon the earth. A similar example involves Christ’s appearance to the Nephites. In this case, man was capitalized in the 1920 edition:
One serious problem, however, with capitalizing one and man in these two examples is that the observers (Lehi in the first case and the Nephites in the second) do not know at this point in the narrative who this person is. The capitalization reveals the identity of the individual before the narrative itself does.
Another problem is that such capitalization of generic nouns is contrary to the entire publishing history of the text. Consistent with usage in the King James Bible, no edition of the Book of Mormon has ever capitalized pronouns or generic nouns that refer to deity. It is true that in the editions the pronoun one is always capitalized when it is used with holy or mighty (“the Holy One of Israel”, “the Mighty One of Jacob”, and so forth). But in 1 Nephi 10:8 (using the language of John 1:26), the generic one is not capitalized (“for there standeth one among you whom ye know not”). And note here that John the Baptist has not yet revealed at this point in the narrative that this “one among you” is the Savior. Similarly, the generic noun man has not been capitalized anywhere except in 3 Nephi 11:8. In the following parallel situation, the word man has never been capitalized in any edition:
Summary: Capitalization of generic nouns such as one and man should be avoided, especially in passages where the narrative itself has not yet revealed that the individual is deity (as in 1 Nephi 1:9, 1 Nephi 10:8, 1 Nephi 11:7, and 3 Nephi 11:8).