Where uses smaller unit than satoshi is being used and by whom? Any reference link for this? Honestly I have been into thoughts about making satoshi as the base unit which also lead me to think about having other units to denote values lesser than one satoshi. But, surprisingly you have mentioned about what was in my mind for years. If your time permits, please share here any reference link for msatt unit. I am just looking for it to enlighten me more on this regard.