netstart(8) lost bridge specific functionality on 2009. Replace "bridge" with "X" in the existent sentence and you'll get a obvious unhelpful statement:
If the network interface is a bridge, the options described in the bridge section of the ifconfig(8) manual page apply. Since the following example is no longer special in any way, remove it. Feedback? OK? Index: hostname.if.5 =================================================================== RCS file: /cvs/src/share/man/man5/hostname.if.5,v retrieving revision 1.78 diff -u -p -r1.78 hostname.if.5 --- hostname.if.5 11 Nov 2021 21:05:46 -0000 1.78 +++ hostname.if.5 25 Jul 2022 23:55:47 -0000 @@ -254,23 +254,6 @@ The .Va autoconf configurations will communicate learned DNS information to .Xr resolvd 8 . -.Sh BRIDGE INTERFACE CONFIGURATION -If the network interface is a bridge, the options described in -the bridge section of the -.Xr ifconfig 8 -manual page apply. -.Pp -For example: -.Bd -literal -offset indent -add fxp0 -add ep1 --learn fxp0 -# -!ipsecctl -F -# -static fxp0 8:0:20:1e:2f:2b -up # and finally enable it -.Ed .Sh FILES .Bl -tag -width "/etc/hostname.XXXXXX" .It Pa /etc/hostname.XXX