It's milifarads, technically lowercase but not often adhered to. Micro is always stamped with u even though it's technically Mu. 100 is huge though, are you sure it isn't .100?
Quoted from EvanDickson:And then some sites convert 10 pf as .01 uf, and some convert 10 pf as .00001 uf
This is going to be because the manufacturers left the decimal point out of the stamp, rather it is implied (67 is actually .067, etc), causing the offset by three digits.