DIYbanter - polarity of low voltage cable?

On Tuesday, May 25, 1999 at 2:00:00 AM UTC-5, Jim Fiocca wrote:
The 14/2 cable that came with my fairly expensive low voltage deck
lights does not have clearly obvious polarity markings. The wiring
instructions refer to the 'ribbed' conductor, but the only markings I
see is some writing on one conductor, which is not continuous. The
little wires coming off the lights themselves have no markings at all
(that I can see).

So my question is, how important is polarity on a 2-wire AC circuit?

Thanks,
Jim