diff --git a/sbin/bectl/bectl.8 b/sbin/bectl/bectl.8
index 4b7868e093eb..79bdec751a86 100644
--- a/sbin/bectl/bectl.8
+++ b/sbin/bectl/bectl.8
@@ -1,377 +1,467 @@
 .\"
 .\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 .\"
 .\" Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\"
 .\"     @(#)be.1
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 6, 2021
+.Dd March 31, 2022
 .Dt BECTL 8
 .Os
 .Sh NAME
 .Nm bectl
 .Nd Utility to manage boot environments on ZFS
 .Sh SYNOPSIS
 .Nm
 .Cm activate
 .Op Fl t | Fl T
 .Ar beName
 .Nm
 .Cm check
 .Nm
 .Cm create
 .Op Fl r
 .Op Fl e Brq Ar nonActiveBe | Ar beName Ns Cm @ Ns Ar snapshot
 .Ar newBeName
 .Nm
 .Cm create
 .Op Fl r
 .Ar beName@snapshot
 .Nm
 .Cm destroy
 .Op Fl \&Fo
 .Ar beName Ns Op Cm @ Ns Ar snapshot
 .Nm
 .Cm export
 .Ar sourceBe
 .Nm
 .Cm import
 .Ar targetBe
 .Nm
 .Cm jail
 .Op Fl bU
 .Oo Bro Fl o Ar key Ns Cm = Ns Ar value | Fl u Ar key Brc Oc Ns ...
 .Ar beName
 .Op Ar utility Op Ar argument ...
 .Nm
 .Cm list
 .Op Fl aDHs
 .Op Fl c Ar property
 .Op Fl C Ar property
 .Oo Bro Fl c Ar property | Fl C Ar property Brc Oc
 .Nm
 .Cm mount
 .Ar beName
 .Op Ar mountpoint
 .Nm
 .Cm rename
 .Ar origBeName
 .Ar newBeName
 .Nm
 .Brq Cm ujail | unjail
 .Brq Ar jailId | jailName | beName
 .Nm
 .Brq Cm umount | unmount
 .Op Fl f
 .Ar beName
 .Pp
 .Nm
 .Op Fl h\&?
 .Sh DESCRIPTION
 The
 .Nm
 command is used to setup and interact with ZFS boot environments, which are
 bootable clones of datasets.
 .Pp
 Boot environments
 allow the system to be upgraded, while preserving the old system environment in
 a separate ZFS dataset.
 .Pp
 The following commands are supported by
 .Nm :
 .Bl -tag -width activate
 .It Xo
 .Cm activate
 .Op Fl t | Fl T
 .Ar beName
 .Xc
 Activate the given
 .Ar beName
 as the default boot filesystem.
 If the
 .Fl t
 flag is given, this takes effect only for the next boot.
 Flag
 .Fl T
 removes temporary boot once configuration.
 Without temporary configuration, the next boot will use zfs dataset specified
 in boot pool
 .Ar bootfs
 property.
 .It Xo
 .Cm check
 .Xc
 Performs a silent sanity check on the current system.
 If boot environments are supported and used,
 .Nm
 will exit with a status code of 0.
 Any other status code is not currently defined and may, in the future, grow
 special meaning for different degrees of sanity check failures.
 .It Xo
 .Cm create
 .Op Fl r
 .Op Fl e Brq Ar nonActiveBe | Ar beName Ns Cm @ Ns Ar snapshot
 .Ar newBeName
 .Xc
 Create a new boot environment named
 .Ar newBeName .
 .Pp
 If the
 .Fl r
 flag is given, a recursive boot environment will be made.
+See
+.Sx Boot Environment Structures
+for a discussion on different layouts.
 .Pp
 If the
 .Fl e
 flag is specified, the new environment will be cloned from the given
 .Ar nonActiveBe
 or
 .Ar beName Ns Cm @ Ns Ar snapshot .
 Otherwise, the new environment will be created from the currently booted environment.
 .Pp
 If
 .Nm
 is creating from another boot environment, a snapshot of that boot environment will be created to clone from.
 .It Xo
 .Cm create
 .Op Fl r
 .Ar beName@snapshot
 .Xc
 Create a snapshot of the boot environment named
 .Ar beName .
 .Pp
 If the
 .Fl r
 flag is given, a recursive snapshot of the boot environment will be created.
 A snapshot is created for each descendant dataset of the boot environment.
+See
+.Sx Boot Environment Structures
+for a discussion on different layouts.
 .Pp
 No new boot environment is created with this command.
 .It Xo
 .Cm destroy
 .Op Fl \&Fo
 .Ar beName Ns Op Cm @ Ns Ar snapshot
 .Xc
 Destroy the given
 .Ar beName
 boot environment or
 .Ar beName Ns Cm @ Ns Ar snapshot
 snapshot without confirmation, unlike in
 .Xr beadm 1 .
 Specifying
 .Fl F
 will automatically unmount without confirmation.
 .Pp
 By default,
 .Nm
 will warn that it is not destroying the origin of
 .Ar beName .
 The
 .Fl o
 flag may be specified to destroy the origin as well.
 .It Cm export Ar sourceBe
 Export
 .Ar sourceBe
 to
 .Xr stdout 4 .
 .Xr stdout 4
 must be piped or redirected to a file.
 .It Cm import Ar targetBe
 Import
 .Ar targetBe
 from
 .Xr stdin 4 .
 .It Xo
 .Cm jail
 .Op Fl bU
 .Oo Bro Fl o Ar key Ns Cm = Ns Ar value | Fl u Ar key Brc Oc Ns ...
 .Ar beName
 .Op Ar utility Op Ar argument ...
 .Xc
 Create a jail of the given boot environment.
 Multiple
 .Fl o
 and
 .Fl u
 arguments may be specified.
 .Fl o
 will set a jail parameter, and
 .Fl u
 will unset a jail parameter.
 .Pp
 By default, jails are created in interactive mode and
 .Pa /bin/sh
 is
 executed within the jail.
 If
 .Ar utility
 is specified, it will be executed instead of
 .Pa /bin/sh .
 The jail will be destroyed and the boot environment unmounted when the command
 finishes executing, unless the
 .Fl U
 argument is specified.
 .Pp
 The
 .Fl b
 argument enables batch mode, thereby disabling interactive mode.
 The
 .Fl U
 argument will be ignored in batch mode.
 .Pp
 The
 .Va name ,
 .Va host.hostname ,
 and
 .Va path
 must be set, the default values are specified below.
 .Pp
 All
 .Ar key Ns Cm = Ns Ar value
 pairs are interpreted as jail parameters as described in
 .Xr jail 8 .
 The following default parameters are provided:
 .Bl -column "allow.mount.devfs" ""
 .It Va allow.mount Ta Cm true
 .It Va allow.mount.devfs Ta Cm true
 .It Va enforce_statfs Ta Cm 1
 .It Va name Ta Set to jail ID.
 .It Va host.hostname Ta Va bootenv
 .It Va path Ta Set to a path in Pa /tmp
 generated by
 .Xr libbe 3 .
 .El
 .Pp
 All default parameters may be overwritten.
 .It Xo
 .Cm list
 .Op Fl aDHs
 .Oo Bro Fl c Ar property | Fl C Ar property Brc Oc
 .Xc
 .Pp
 Display all boot environments.
 The
 .Em Active
 field indicates whether the boot environment is active now
 .Pq Em \&N ;
 active on reboot
 .Pq Em \&R ;
 is used on next boot once
 .Pq Em \&T ;
 or combination of
 .Pq Em \&NRT .
 .Pp
 .Bl -tag -width indent
 .It Fl a
 Display all datasets.
 .It Fl D
 Display the full space usage for each boot environment, assuming all
 other boot environments were destroyed.
 .It Fl H
 Used for scripting.
 Do not print headers and separate fields by a single tab instead of
 arbitrary white space.
 .It Fl s
 Display all snapshots as well.
 .It Fl c Ar property
 Sort boot environments by given property name.
 The following properties are supported:
 .Pp
 .Bl -tag -width 4n -offset indent -compact
 .It name (default output)
 .It creation
 .It origin
 .It used
 .It usedds
 .It usedsnap
 .It usedrefreserv
 .El
 .It Fl C Ar property
 Same as the
 .Fl c
 option, but displays in descending order.
 .El
 .Pp
 The
 .Fl D
 option is ignored when either the
 .Fl s
 or
 .Fl a
 option is used.
 .It Cm mount Ar beName Op Ar mountpoint
 Temporarily mount the boot environment.
 Mount at the specified
 .Ar mountpoint
 if provided.
 .It Cm rename Ar origBeName newBeName
 Rename the given
 .Ar origBeName
 to the given
 .Ar newBeName .
 The boot environment will not be unmounted in order for this rename to occur.
 .It Cm ujail Brq Ar jailId | jailName | beName
 .It Cm unjail Brq Ar jailId | jailName | beName
 Destroy the jail created from the given boot environment.
 .It Xo
 .Cm umount
 .Op Fl f
 .Ar beName
 .Xc
 .It Xo
 .Cm unmount
 .Op Fl f
 .Ar beName
 .Xc
 Unmount the given boot environment, if it is mounted.
 Specifying
 .Fl f
 will force the unmount if busy.
 .El
 .Pp
 .Nm
 prints usage information if
 .Fl h
 or
 .Fl \&?
 is specified.
+.Ss Boot Environment Structures
+The traditional
+.Fx
+boot environment layout, as created by the Auto ZFS option to
+.Xr bsdinstall 8 ,
+is a
+.Dq shallow
+boot environment structure, where boot environment datasets do not have any
+directly subordinate datasets.
+Instead, they're organized off in
+.Pa zroot/ROOT ,
+and they rely on datasets elsewhere in the pool having
+.Dv canmount
+set to
+.Dv off .
+For instance, a simplified pool may be laid out as such:
+.Bd -literal -offset indent
+% zfs list -o name,canmount,mountpoint
+NAME			CANMOUNT	MOUNTPOINT
+zroot
+zroot/ROOT		noauto		none
+zroot/ROOT/default	noauto		none
+zroot/usr		off		/usr
+zroot/usr/home		on		/usr/home
+zroot/var		on		/var
+.Ed
+.Pp
+In that example,
+.Pa zroot/usr
+has
+.Dv canmount
+set to
+.Dv off ,
+thus files in
+.Pa /usr
+typically fall into the boot environment because this dataset is not mounted.
+.Pa zroot/usr/home
+is mounted, thus files in
+.Pa /usr/home
+are not in the boot environment.
+.Pp
+The other style of boot environments in use, frequently called
+.Dq deep boot environments ,
+organizes some or all of the boot environment as subordinate to the boot
+environment dataset.
+For example:
+.Bd -literal -offset indent
+% zfs list -o name,canmount,mountpoint
+NAME				CANMOUNT	MOUNTPOINT
+zroot
+zroot/ROOT			noauto		none
+zroot/ROOT/default		noauto		none
+zroot/ROOT/default/usr		noauto		/usr
+zroot/ROOT/default/usr/local	noauto		/usr/local
+zroot/var			on		/var
+.Ed
+.Pp
+Note that the subordinate datasets now have
+.Dv canmount
+set to
+.Dv noauto .
+These are more obviously a part of the boot environment, as indicated by their
+positioning in the layout.
+These subordinate datasets will be mounted by the
+.Dv zfsbe
+.Xr rc 8
+script at boot time.
+In this example,
+.Pa /var
+is excluded from the boot environment.
+.Pp
+.Nm
+commands that have their own
+.Fl r
+operate on this second,
+.Dq deep
+style of boot environment, when the
+.Fl r
+flag is set.
+A future version of
+.Nm
+may default to handling both styles and deprecate the various
+.Fl r
+flags.
 \" .Sh EXAMPLES
 \" .Bl -bullet
 \" .It
 \" To fill in with jail upgrade example when behavior is firm.
 \" .El
 .Sh SEE ALSO
 .Xr libbe 3 ,
 .Xr beinstall.sh 8 ,
 .Xr jail 8 ,
 .Xr zfs 8 ,
 .Xr zpool 8
 .Sh HISTORY
 .Nm
 is based on
 .Xr beadm 1
 and was implemented as a project for the 2017 Summer of Code, along with
 .Xr libbe 3 .
 .Sh AUTHORS
 .Nm
 was written by
 .An Kyle Kneitinger (kneitinger) Aq Mt kyle@kneit.in .
 .Pp
 .Xr beadm 1
 was written and is maintained by
 .An Slawomir Wojciech Wojtczak (vermaden) Aq Mt vermaden@interia.pl .
 .Pp
 .An Bryan Drewery (bdrewery) Aq Mt bryan@shatow.net
 wrote the original
 .Xr beadm 1
 manual page that this one is derived from.