Earlier today, @gregmac created the thermostat-c-wire tag (and its tag wiki) and applied it to all the questions that we have about "C" wires.
A couple of times, I had thought about doing the same when I saw these questions come up on the home page, except the tag I was thinking of adding was c-wire. I believe thermostat-c-wire is the better tag because it's more descriptive. However, to date most of the people asking these questions are new users (13 of the 17 OPs), and might not realize how the tagging system works here: that they'd need to add both thermostat and thermostat-c-wire.
To that end, would creating a synonym c-wire for the main tag thermostat-c-wire be useful?