For values including undefined:

system domain Value

For general use to calculate with value maps.

system domain Distance

Designed to calculate distances; unit 'm'.

system domain Count

Designed to count values that are not undefined; fixed precision.

system domain Min1to1

Designed to calculate with values from -1.00 to +1.00; fixed value range.

system domain NILto1

Designed to calculate with values from 0.00 to +1.00; fixed value range.

system domain Perc

Designed to calculate with percentage values; unit '%'.

system domain Byte

To calculate with images which have a value range from 1 to 255; where 0 should mean undefined; fixed value range and precision.

For satellite imagery:

system domain Image

For images with integer values from 0 to 255.

system domain NOAA

For NOAA images with integer values from 0 to 1023.

system domain Radar

For Radar images with integer values from 0 to 32767.

For Boolean values and undefined:

system domain Bool

To calculate with boolean values True, False and undefined.

system domain YesNo

To calculate with boolean values Yes, No and undefined.

For Boolean values and no undefined:

system domain Bit

To calculate with values 0 and 1 (deprecated).

Other:

system domain String

To use in columns that should contain plain texts such as descriptions.

system domain UniqueID

To use in maps in which each mapping unit should obtain its own unique ID.

system domain Color

To use for colored images (256 x 256 x 256 colors).

system domain ColorCmp

Is used as output domain by the Color Composite operation.

system domain FlowDirection

To calculate with eight compass directions: N (to the North), E (to the East), S, W, NE, SE, SW, NW. Fixed output domain for the Flow direction operation.

system domain None

For tables that have no class or ID domain, i.e. when the table should simply store records.