Random lurker with random question...

I just got a new scale. After the third time of reading the instructions, finally got the fancy thing to work.

One of the numbers it is giving me is bone mineral mass. But, nowhere in the instruction book does it say a word about what I should be doing with this info, or what it means. Nice charts for the body fat and body water.... but not a word about the bone number.

Searching online I'm not finding anything about bone mass that measures in pounds like this does.... everything google keeps giving me is about density and uses total different numbers.

What exactly do I do with this? Is there a point to knowing this number besides just giving me an excuse to subtract something?
Is there a normal vs big bones range?
It wouldn't seem like bone mass would be something that would change much.. is this a number I should even bother writing down each time?

Personally, the way I see this is to just notice a trend. I think the intention of this reading is to see if you are losing bone mass as a result of your dieting. But the only way to assess this accurately is through bone density scans, so the scale number, while interesting, may not be terribly useful. I WOULD keep an eye on it, though, say, once a month, if I was on a high protein diet as your body will take calcium from your bones to digest excess protein, causing osteoporosis (or brittle bones)...
I think scales give so much useless info because the assumption is the more measurements given, the better the scale "must" be...
Kira