Fan Header wiring

I want to install an IP camera at a remote site where we have had a few problems, but I also need the ability to turn it on and off to preserve battery power if necessary.

I have an RB433AH on-site and note that elsewhere Normis has suggested using the fan header as a switch. However to do that I need to be let into the secret of the wiring of the header pins, which seems to be non-ATX.

I know this is more than MT can be expected to make public off its own bat but has anyone puzzled it out without wrecking a few 433s in the process? Or is there some arcane Latvian ritual involving moonlight, honey, black cats and the blood of virgins that I have to go through in order to have the secret revealed to me?