chflags "archived" flag?

[Paul M. Lambert]

Ok, I'm stumped.  Call me stupid, but...

chflags(1) and chflags(2) and chflags(3) all mention SF_ARCHIVED as a flag
that the superuser can set on a file or directory.

My question is simple: what's this flag do?  Does it have any effect?

A 'find /usr/src -type f -print | xargs grep -li SF_ARCH' gives me no
new info...  nothing there seems to actually be affected by the flag.

So, what am I missing?  What does it do?

Thanks!

--plambert