Function store_others 

fn store_others(
    root: &Path,
    cert: Cert,
    learned: &[String],
) -> Result<KeySummary, String>

Keeps someone’s key for learned: the address it came for (a key from elsewhere comes cut to it, for_its_address) or, imported from a file you chose, every address bound to it. Merged with the one kept, it serves what it served and these (its file beside, written first), cut to their user IDs: an address a key kept before, or an older Sioul’s write, named besides is never kept nor served (review of 19 October 2026, N2), and the user IDs of an address it was learned for before stay.