You can define a code table in the module model and use it to define entity attributes. Code tables are created within a folder.
After creating a code table, you can define an entity attribute where the value of the attribute is a code table value (type code). A type code attribute is defined in a similar way to the primitive–typed attribute, but you must set the ‘code table' property to point to the associated code table.
After defining the code tables, additional associated code is generated.