[ceph-users] Is ceph bootstrap keyrings in use after bootstrap?

Hi, I'm on Ceph version 16.2.10, and I found there are a bunch of bootstrap keyrings (i.e., client.bootstrap-<mds|mgr|osd|rbd|rbd-mirror|rgw>) located at /var/lib/ceph/bootstrap-<mds|mgr|osd|rbd|rbd-mirror|rgw>/ceph.keyring after bootstrap. Are they still in use after bootstrap? Is it safe to remove them from host and even from ceph monitor? Thanks, Zhongzhou Cai