I'm putting my bike back together and trying to set the timing.  I took off the pulse generator coil cover looking for the R.T. mark that the Haynes manual talks about and it's not there. 

Instead I have a "T" and the letters "VHF" or something like that, I can't remember what the last letter was, but I think it was an "F".

Any idea what this is and how to tell if it's TDC so that I can set everything up and get this thing running?

you have a california bike, no?

Yeah

You have a V&H Racing advancer...VHR. They have the T (which is close to the tab), the R is not marked but it is opposite the T.