Core Data - iOS Programming: The Big Nerd Ranch Guide - page 483

This will create a Homepwner.xcdatamodeld file and add it to your project. Select
this file from the project navigator, and the editor area will reveal the user interface for
manipulating a Core Data model file.
Find the Add Entity button at the bottom left of the window and click it. A new Entity will
appear in the list of entities in the lefthand table. Double-click this entity and change its
name to BNRItem ( Figure 16.4 ).
Figure 16.4 Create the BNRItem entity