help understanding timing marks

I've never really delt with timing marks before...and I'm trying to get my new balancer installed and make sure my marks line up...

1. Should the TDC be a 0 degree mark?

2. I have a balancer I took off that was like this: TDC, 10, 0, 10, 20, 30 etc and the TDC did not have any line/mark just the letters. Is TDC at the TDC or at the zero? I'm confused by this because my new balancer does not say TDC or BDC it just starts at 0 then goes 10, 20 30 etc. Why does my old balancer have the TDC, 10 before the zero?

Don't ask me to say where TDC was on my old balancer....I think it was wrong anyways...I guess I just want to know if 0 is where I should align my TDC markings to perhaps using timing tape to accomplish this.
 
TDC should be at the 0° mark on the balancer.

It should look like this:
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
20........15........10..........5...........0.........5..........10
BTDC.......................................TDC.................ATDC

I think I have those backwards, but it took me long enough to get the alignment right that I'm not fixing it. :rlaugh: The zero would equal TDC for the number 1 cylinder on either the compression/power stroke, or the exhaust stroke.