What is direction ancillary indication?

Well, Ancillary indication means a subordinate or "back" up indicator. So a Direction Ancillary Indication would mean a supported, subordinate "backup" indication of your direction.

If you mean Driection Ancillary Indicator: It is a simple tool, mainly used in the outdoors, that tells direction.

Many come on a multi-tool. It's a circular hole through in a flat piece of a hard material like steel, titanium, plastic..etc, with increments etched around it's edge.

1.You place this flat on a flat surface.

2. You drop a few drops of water in its center.

3. Magnetize a very light piece of metal.( So that it will float on the surface tension of the water. This can be done by a magnet, but I'vealso hear you can magnetize it by rubbing it on your hair. Odd, since I'd think you'd only produce static electricity, but eh,..I'll test that when I get an indicator.)

4. Lay shaving, pin..etc. on top of water.

5. Result should be the ends pointing toward magnetic north and south.