Question: Two-row connector blocks are ubiquitous in small-run and hobbyist PCB designs. Pitches of 0.1" or 2mm are the most common, and there are all sorts of options for board-to-board or board-to-wire connectors. The problem is that pin numbering schemes vary wildly.

Pin numbering schemes I've seen include:

1. DIP-style counterclockwise: ![DIP number scheme, taken from Wikipedia](https://i.stack.imgur.com/JbOW1.png)
2. Zig-zag between the two rows: ![Molex Milligrid numbering scheme](https://i.stack.imgur.com/CBSgL.png)
3. Down one row then the other, but NOT counterclockwise: ![Molex Micro-fit numbering scheme](https://i.stack.imgur.com/tXvtR.png)

In my experience, getting the pin numbers wrong is one of the most common sources of PCB heartbreak. I've done a lot of wire patching to correct 6-pin header layout mistakes... and I've thrown away boards with 70-pin header errors.

My question is: **Are there industry standard terms for these (or other) 2-row pin numbering schemes?**

I would love to have a short, reliable way to specify these schemes, to allow saying things like "We're using a 14-pin 0.1" header with *zig-zag* numbering" (or whatever).

Although standardized names with the broadest possible user base are (obviously) better, I realize that there probably isn't one true answer to this question. I'd appreciate answers about how these schemes are named even within smaller subsets of the industry, as long as you're clear about the scope of use (e.g. "At company X we always called the second scheme 'shoelacing'").

Answer: 
If You are using/connecting flat/ribbon cable than pin numbering must be zig-zag, because of cable construction. 
It is also depending on software you are using for develop pcb.
In my experience in repairing boards, more or less 1st pin is somehow visibile, other wires mark as for your convenience.
Happy HW connecting.
Pin 1 generally gets a square pad on the PCB as an index marker, whereas those of the other pins are generally round.