We used Staff notes for tagging a topic with a link to a ticket in our ticketing system, which we don’t want visible to non-staff.
It appears that something like the following will work for us (thank you @Lilly):
.post-notice.custom {
display: none;
}
.staff .post-notice.custom {
display: initial;
}
Agree that this isn’t particularly safe, just need to do something stopgap until we transition away from this usage.