passwd -S Alternate authentication scheme in use

in RHEL 7.9, I do passwd -S on all accounts in /etc/passwd as part of checking user accounts. # passwd -S root PS 1969-12-30 0 99999 7 -1 (Password set, SHA512 crypt.) bin LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) daemon LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) adm LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) lp LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) sync LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) shutdown LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) halt LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) mail LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) operator LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) games LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) ftp LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) nobody LK 2019-08-22 0 99999 7 -1 (Alternate authentication scheme in use.) systemd-network LK 2021-06-10 -1 -1 -1 -1 (Password locked.) dbus LK 2021-06-10 -1 -1 -1 -1 (Password locked.) polkitd LK 2021-06-10 -1 -1 -1 -1 (Password locked.) libstoragemgmt LK 2021-06-10 -1 -1 -1 -1 (Password locked.) ron PS 2021-09-06 1 90 14 5 (Password set, SHA512 crypt.) This is a clean install of RHEL 7.9 x86-64 from dvd. Above is an excerpt from doing passwd -S on all accounts in /etc/passwd. Can someone enlighten me what (Alternate authentication scheme in use.) means and if it would be prudent to perform some kind of passwd or chage command (and if so what) on those accounts? Basically I am anticipating during an audit the *show me how you secure and manage user accounts* question so I explain *I do passwd -S on all accounts in /etc/passwd* but how do I explain away the *Alternate authentication scheme in use*? fwiw, I am doing chage -m 1 -M 90 -W 14 -I 5 on all my regular user accounts.