THIS OTHER LOGGING THREAD has some pretty good info. I linked to page 14, since it had some specific explanations of UPT time, but the whole thread is good. In a few other convos I've had, I'm of the understanding that if you have a PPL and an ASEL rating, you CAN log T6 time as PIC on flights you are the sole manipulator of the controls. It won't count as "sign for the plane" PIC time that some airlines are counting, but it does count as PIC since you are the sole manipulator.
YMMV and opinions seem to differ, but that's my take...