The entity files use the .cdl file extension and must be formatted using the following tab delimited structure.

Entity Search Text<tab>Entity Label<tab>Normalized Entity Name

Entity Label and Normalized Entity Name are optional, but recommended.

If the file contains values for the Normalized Entity Name, this is what is returned by the Natural language processing engine.

For example, your .cdl file contains the following content.

Dog	<empty>	Canine
Cat	<empty>	Feline

When extraction is performed, the NLP engine returns either Canine or Feline rather than Dog or Cat.