You can assign each region a class to differentiate it from other regions of the same type, e.g. to have different classes of analysis regions. Classes are commonly used to associate regions with a particular target species but may be used for any logical grouping of regions.
You can choose to make different region classes visible on different echograms on the Regions page of the Variable Properties dialog box (if a region class is not visible on an echogram the regions within that class will not be used in analyses).
You can manually classify regions or classify 2D regions with Rules. Refer to Classifying regions for more information.
About regions
Classifying regions
Region Classification tool
Species Properties dialog box
Species Allocation dialog box
Exporting biomass estimates