Table 2: Non-linear algorithm codes, (characters 6-8 of CTYPE ).

	Regularly
Code	sampled in	Expressed as
F2W	Frequency	Wavelength
F2V	Frequency	Apparent radial velocity
F2A	Frequency	Air wavelength
W2F	Wavelength	Frequency
W2V	Wavelength	Apparent radial velocity
W2A	Wavelength	Air wavelength
V2F	Apparent radial velocity	Frequency
V2W	Apparent radial velocity	Wavelength
V2A	Apparent radial velocity	Air wavelength
A2F	Air wavelength	Frequency
A2W	Air wavelength	Wavelength
A2V	Air wavelength	Apparent radial velocity
LOG	logarithm	Any 4-letter coordinate type
GRI	detector	Any from Table 1
GRA	detector	Any from Table 1
TAB	not regular	Any 4-letter coordinate type