Scribe 2 of 𝓟 accidentally omitted the title for the book of Alma, probably because of its visual similarity to the preface of the book, which immediately follows:
Oliver Cowdery, in his proofing of 𝓟 against 𝓞, restored the title. The full title of the third book of Nephi is similar in that it too contains a genealogical description:
Summary: Oliver Cowdery’s inserted title for the book of Alma, with its additional specification “the Son of Alma”, was undoubtedly in the original manuscript but was accidentally omitted by scribe 2 of 𝓟 when he copied the text from 𝓞 into 𝓟.