-.\" $OpenBSD: BIO_f_null.3,v 1.10 2022/12/18 19:35:36 schwarze Exp $
+.\" $OpenBSD: BIO_f_null.3,v 1.11 2022/12/23 16:59:39 schwarze Exp $
.\" full merge up to: OpenSSL e9b77246 Jan 20 19:58:49 2017 +0100
.\"
.\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
.\" OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd $Mdocdate: December 18 2022 $
+.Dd $Mdocdate: December 23 2022 $
.Dt BIO_F_NULL 3
.Os
.Sh NAME
.Nm BIO_f_null
+.\" .Nm BIO_f_nbio_test is intentionally undocumented
+.\" because it exposes absurd functionality that is unused
+.\" except in openssl(1) s_client/s_server -nbio_test.
.Nd null filter
.Sh SYNOPSIS
.In openssl/bio.h