Refer to figure.
Unfortunately, Airspeed Indicators (ASIs) produce their own errors because of manufacturing inaccuracies, friction within the instrument, and even the positioning of the static pressure ports.

The only differences between CAS and IAS are the position and instrument errors:

• Instrument errors are caused by the manufacturer, and all the instruments will be affected. A coefficient will be included in the calibration formula to bring the necessary correction for the instrument error.
• The pressure (position) error is caused by the position of the static ports, resulting in the airflow disturbance around the aircraft. This error may be influenced by many factors, such as the aircraft's angle of attack, speed (Mach number, TAS, etc.), sideslip, configuration, etc.

The pressure error correction can be found in a table in the aircraft operations manual. Combined with the instrument error, it may be displayed on a correction card fitted next to each ASI so that the flight crew can apply to the IAS both error corrections and obtain the CAS.

Therefore, the correct answer is "indicated airspeed (IAS) corrected for instrument and position error."