In the RPiconfig list of command at eLinux.org (http://elinux.org/RPiconfig
hdmi_ignore_cec_init Doesn't sent initial active source message. Avoids bringing (CEC enabled) TV out of standby and channel switch when rebooting.
hdmi_ignore_cec Pretends CEC is not supported at all by TV. No CEC functions will be supported.
So if you just want to keep it from switching during reboot you use the first one. If you want to disable commands completely use the second.