c: Copyright (C) 1998 - 2022, Daniel Stenberg, , et al. SPDX-License-Identifier: curl Short: 1 Long: tlsv1 Tags: Versions Protocols: SSL Added: 7.9.2 Mutexed: tlsv1.1 tlsv1.2 tlsv1.3 Requires: TLS See-also: http1.1 http2 Help: Use TLSv1.0 or greater Category: tls Example: --tlsv1 $URL --- Tells curl to use at least TLS version 1.x when negotiating with a remote TLS server. That means TLS version 1.0 or higher