Where Enos appeared to have imitated Nephi in the opening of his book, Jarom does not. Jarom begins by saying that he really won’t be saying much. In his case, it is not because of unrighteousness, for he had received revelations and had prophesied. What he will write about is that those teachings, as those that Enos had described, do not appear to have been effective. Jarom will continue the theme of his fathers, who lamented the Nephite departure from the path of righteousness.
In verse 1, Jarom makes the interesting statement that his father commanded that the genealogy might be kept. Enos didn’t give a genealogy and Jarom will not either. The only time Nephi mentioned the genealogy of his fathers, he specifically said that he would not include it (see 1 Nephi 5:16 and 1 Nephi 6:1).
As with the complicated meanings that appear to surround the idea of being taught language, the idea of what genealogy meant in this context must be deduced. In this case, it probably indicates the family connection of writing on the plates. These plates passed from father to son, with some instances of brother to brother. That is the genealogy to be kept.
Confirmation that this is the intended meaning could be that the very next thing Jarom speaks about is writing on the plates. Thus, keeping the genealogy and writing on the plates were connected. The only link to family is the responsibility to write.