Milli Bits: mBTC = milli bitcoin = 1 thousandth of a bitcoin = 0.001BTC
Huh? Milli stands for one thousandth.
You are right that 1 mBTC = 0.001 btc, but 1 "milli bit" (if such unit exists) should be 0.001 "bit" which doesn't make sense as the smallest bitcoin unit is satoshi (0.01 bit).