The Curl man page lists -1 --tlsv1 and separately lists --tlsv1.0 along with v1.1 and v1.2.
The descriptions are:
-1, --tlsv1
(SSL) Forces curl to use TLS version 1 when negotiating with a remote TLS server.
And later:
--tlsv1.0
(SSL) Forces curl to use TLS version 1.0 when negotiating with a remote TLS server. (Added in 7.34.0)
Is there a difference between these tlsv1 and tlsv1.0 options?