SAC terminology

[Willem Ferguson]

I am doing a technical qualification with IANTD and they use SAC as the 
rate of decrease per minute in the pressure in the gas cylinder 
(units=bar/minute). Then I went back to some of my TDI and NAUI notes 
and came across the same definition. This use of SAC would remove the 
interchangeability that is often encountered between SAC and RMV, with 
RMV indicating the gas consumption in volume/minute (e.g. 
liters/minute). Is this something worth worrying about for the SAC rate 
given on the dive info panel?
Kind regards,
Willemf