Interconnects, some have directional indicators, why?


I'm curious as to why some interconnects are directional? Is there a physical internal difference and do they generally sound better and cost more than non-directional cables? Thanks for your interest.
phd
Post removed 
sorry to report, atmasphere, the dude from Audioquest was actually referring to folks like you who insist that any directionality in the sound is due to the shield and who keep insisting there is not such thing as wire directionality whether it be fuses, cables, interconnects what have you. Mr. Low, in fact, is quite outspoken in this regard. Maybe you better read the article again.

Let’s summarize, shall we? copper and any metal wire is direction, both in measurement and in listening. If there is a difference is sound for shielded cables of any type due only to the direction of the sheld the manufacturer of that cable would be well advised to consider the directionality of the conductor as well, you know, in order to acheive maximum results. What cable manufacturer - unless he's lived in a cave somewhere for the past 30 years -wouldn’t do that? By the same token, any cable manufacturer who doesnt employ cryogenic treatment is living in the eighties. Its really a question of staying competitive, at least for the high end. I actually don’t care about mid fi particularly. 
Who inspects the cable to ensure the crystals are properly aligned and then decides which way is best for optimum signal flow? And after this is determined, who, at the factory ensures the cable has the proper orientation? 
Something smells fishy to me here.
Sorry to report, atmasphere, the dude from Audioquest was actually referring to folks like you who insist that any directionality in the sound is due to the shield and who keep insisting there is not such thing as wire directionality whether it be fuses, cables, interconnects what have you. Mr. Low, in fact, is quite outspoken in this regard. Maybe you better read the article again.
Please refer to my original post regarding this ridiculous topic, in which I was careful to include this text:

The above quote is from Audioquest and shows how its the shield connection that is causing the directionality, despite their awareness of how the crystals initially align in their wire.

We've built amps with Audioquest wire before. At the time of installation, Audioquest made no mention whatsoever about directionality.
And also:
If that is not the case and somehow Audioquest was trying to make a point about wire being directional and ***nothing else*** than this paragraph isn't their best marketing.
Emphasis added.

Again, if a wire really has directionality (a **wire** mind you, not a cable) in an AC circuit it will be demonstrating diode characteristics, which will induce a DC voltage at the output. Since this does not happen, again (since I am repeating myself) we know that in fact whether the crystals in a wire have a particular orientation is moot; the wire itself has no directionality whatsoever.

I am sure this is why no instruction accompanied the hookup wire we obtained from Audioquest.
Something smells fishy to me here.
You are correct. Its an obvious hoax.