diff --git a/usr.sbin/bootparamd/callbootd/callbootd.8 b/usr.sbin/bootparamd/callbootd/callbootd.8
new file mode 100644
--- /dev/null
+++ b/usr.sbin/bootparamd/callbootd/callbootd.8
@@ -0,0 +1,96 @@
+.\"
+.\" Copyright (c) 2025 Felix Johnson
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.Dd June 23, 2025
+.Dt CALLBOOTD 8
+.Os
+.Sh NAME
+.Nm callbootd
+.Nd Contact boot parameter server for boot parameters
+.Sh SYNOPSIS
+.Nm
+.Ar server
+.Ar client
+.Op file_id
+.Sh DESCRIPTION
+The
+.Nm
+utility is a client application that provides information to
+.Xr diskless 8
+clients necessary for booting.
+.Nm
+runs after the kernel initializes networking
+but before mounting the root filesystem.
+It retrieves hostname, domain, router, and
+NFS boot file information from
+.Xr bootparamd 8 .
+This information is used to configure networking
+and mount NFS filesystems.
+.Pp
+If
+.Ar file_id
+is not specified,
+.Nm
+will contact
+.Ar server
+and request the client name, domain name,
+and default router associated with
+.Ar client .
+.Pp
+If
+.Ar file_id
+is specified,
+.Nm
+will contact
+.Ar server
+to request the boot server name, boot server address,
+and NFS path associated with
+.Ar client
+and
+.Ar file_id .
+.Sh OPTIONS
+.Bl -tag -width "file_id"
+.It Ar server
+Contact
+.Ar server
+to request boot parameters.
+If server is "all", a broadcast message is sent
+to all hosts on the local network.
+.It Ar client
+The IP address or hostname of the client.
+.It Op file_id
+The NFS export path associated with
+.Ar client
+and
+.Ar file_id .
+.El
+.Sh EXAMPLES
+To request information from server 192.168.0.3
+for client 192.168.0.20:
+.Pp
+.Dl callbootd 192.168.0.3 192.168.0.20
+.Pp
+To request information from anyone on the local network:
+.Pp
+.Dl callbootd all 192.168.0.20
+.Pp
+To request the NFS path for the "root" export from
+server 192.168.0.3 for client "rusty":
+.Pp
+.Dl callbootd 192.168.0.3 rusty root
+.Sh SEE ALSO
+.Xr bootparams 5 ,
+.Xr bootparamd 8 ,
+.Xr diskless 8
+.Sh AUTHORS
+.Nm
+was written by
+.An Klas Heggemann Aq Mt klas@nada.kth.se .
+.Pp
+This manual page was written by Felix Johnson
+.Aq Mt felix.the.red@gmail.com .
+.Sh BUGS
+.Nm
+only supports IPv4.
diff --git a/usr.sbin/bootparamd/callbootd/callbootd.c b/usr.sbin/bootparamd/callbootd/callbootd.c
--- a/usr.sbin/bootparamd/callbootd/callbootd.c
+++ b/usr.sbin/bootparamd/callbootd/callbootd.c
@@ -149,8 +149,7 @@
 static void
 usage(void)
 {
-	fprintf(stderr,
-		"usage: callbootd server procnum (IP-addr | host fileid)\n");
+    errx(stderr, "usage: callbootd server client [file_id]\n");
     exit(1);
 }