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+This menu allows you to configure the Securelevel mechanism in FreeBSD.
+
+Securelevels may be used to limit the privileges assigned to the
+root user in multi-user mode, which in turn may limit the effects of
+a root compromise, at the cost of reducing administrative functions.
+Refer to the init(8) manual page for complete details.
+
+   -1    Permanently insecure mode - always run the system in level 0 mode.
+         This is the default initial value.
+
+   0     Insecure mode - immutable and append-only flags may be turned off.
+         All devices may be read or written subject to their permissions.
+
+   1     Secure mode - the system immutable and system append-only flags may
+         not be turned off; disks for mounted file systems, /dev/mem, and
+         /dev/kmem may not be opened for writing; kernel modules (see
+         kld(4)) may not be loaded or unloaded.
+
+   2     Highly secure mode - same as secure mode, plus disks may not be
+         opened for writing (except by mount(2)) whether mounted or not.
+         This level precludes tampering with file systems by unmounting
+         them, but also inhibits running newfs(8) while the system is multi-
+         user.
+
+         In addition, kernel time changes are restricted to less than or
+         equal to one second.  Attempts to change the time by more than this
+         will log the message ``Time adjustment clamped to +1 second''.
+
+   3     Network secure mode - same as highly secure mode, plus IP packet
+         filter rules (see ipfw(8) and ipfirewall(4)) cannot be changed and
+         dummynet(4) configuration cannot be adjusted.
+
+Securelevels must be used in combination with careful system design and
+application of protective mechanisms to prevent system configuration
+files from being modified in a way that compromises the protections of
+the securelevel variable upon reboot.