Index: share/man/man5/freebsd-update.conf.5
===================================================================
--- share/man/man5/freebsd-update.conf.5
+++ share/man/man5/freebsd-update.conf.5
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 19, 2009
+.Dd February 4, 2022
 .Dt FREEBSD-UPDATE.CONF 5
 .Os FreeBSD
 .Sh NAME
@@ -218,6 +218,42 @@
 .Cm freebsd-update
 rollback command will recreate the symbol files along with the old
 kernel.
+.It Cm CreateBootEnv
+The single parameter following this keyword must be
+.Dq yes
+or
+.Dq no
+and specifies whether
+.Cm freebsd-update
+will create a new boot environment using
+.Xr bectl 8
+when installing patches.
+.Pp
+The name of the new boot environment consists of the current
+.Fx
+kernel version
+and a timestamp
+separated by a single dash, e.g.:
+.Bd -literal -offset indent
+12.0-RELEASE-p10_2019-10-03_185233
+.Ed
+.Pp
+The implementation of the name generation is equivalent to the following
+.Xr sh 1
+one-liner:
+.Bd -literal -offset indent
+$(freebsd-version -k)-$(date +"%Y-%m-%d_%H%M%S")
+.Ed
+.Pp
+.Cm freebsd-update
+does not attempt to create a boot environment if:
+.Bl -dash -compact
+.It
+UFS is used.
+.It
+.Cm freebsd-update
+is running in a
+.Xr jail 8 .
 .El
 .Sh FILES
 .Bl -tag -width "/etc/freebsd-update.conf"
@@ -228,6 +264,7 @@
 .El
 .Sh SEE ALSO
 .Xr sha256 1 ,
+.Xr bectl 8 ,
 .Xr freebsd-update 8
 .Sh AUTHORS
 .An Colin Percival Aq Mt cperciva@FreeBSD.org