Hmm. Some slight misinformation going on here. But rather than paraphrase the correct answers, I tried google and came up with this:

http://www.filterforge.com/more/help/MainWindow/RenderMapsMenu.html

All you need to know about those maps. Well, except how to use them in the Poser material room.

 The metallic map is tricky. To use it effectively, you have to understand the difference between a dialectric and a metal. The two main differences (simplified answer here of course, otherwise we're going to need physics book) are:

A dialectric produces specular reflections in the same color as the light source, while a metal colors the speculars just like the diffuse reflections. In other words, on yellow plastic (a dialectric) a specular reflection is usually white, while on yellow gold it is yellow.

A dialectric usually has a fairly low index of refraction, while metals are often in the hundreds. This means that for a dialectric, the Fresnel effect is really important, while for a metal it is not. The Fresnel effect, basically, is that a material facing the camera reflects less than one that faces sideways.

To implement these effects you have to use nodes - there is no simple PoserSurface input for metallic versus dialectric.

If you really have a Filter Forge material that actually produces this map, show me and I'll build a Poser shader for it, so you see how its done.

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