Dont know what i did to get on your respected list, but i guess that i better answer this properly to keep myself there.......
ASIR = Airspeed Indicator Reading, the uncorrected reading of the airspeed indicator.
IAS= Indicated Airspeed, the ASIR corrected for instrument error only.
RAS = Rectified Airspeed, the IAS corrected for position error.
EAS = Equivalent Airspeed, IAS corrected for position error and compressibility error.
CAS = Calibrated Airspeed, An Amercian term for EAS at sea level only.
TAS = True airspeed, the true speed of an aircraft through undisturbed air.
Position Error = The total error in the pressure instrument readings due to the position and limitations of the pitot static system.
Compressibility Error, the error in pressure instrument readings due to Mach Number effect.....
These are taken from my ATP notes, so basically IAS is corrected for instrument error. CAS and EAS are the same thing and equate to IAS corrected for position error and compressibility.
Does this keep me on your list...