Host my.host.com
    HostName my.host.com
    User michael
    Port 1234

Host m
    HostName my.host.com
    User michael
    Port 1234

ssh: Could not resolve hostname m: Name or service not known

OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014 debug1: Reading configuration
data /root/.ssh/config debug1: Reading configuration data
/etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying
options for * ssh: Could not resolve hostname m: Name or service not
known

OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /root/.ssh/config
debug1: /root/.ssh/config line 11: Applying options for z