Based on the text in faq14.html, but using the manpage language.
diff --git share/man/man4/softraid.4 share/man/man4/softraid.4
index 4fa72dd6e..98897c7dd 100644
--- share/man/man4/softraid.4
+++ share/man/man4/softraid.4
@@ -201,6 +201,10 @@ There is no point in wasting a lot of time syncing random
data.
The RAID 5 discipline does not initialize parity upon creation, instead parity
is only updated upon write.
.Pp
+Stacking disciplines (CRYPTO on top of RAID 1, for example) is
+.Em not supported
+at this time.
+.Pp
Currently there is no automated mechanism to recover from failed disks.
.Pp
Certain RAID levels can protect against some data loss
