There are a few important model properties. This dialog box allows you to view or edit the following properties: the model font (its face and size), whether the primary keys migration mechanism should be used, whether the border should be used while printing the model.

Key migration is a mechanism when the primary key fields of the parent table (entity) become a part of the child table either getting into the primary key or not depending on whether the identifying or non-identifying relationship is used.
The parent entity is requited for identifying relationship while in case with non-identifying relationship the NULL value is acceptable for the field corresponding to the relationship.

Identifying relationships are shown with the help of continuous lines, while Non-identifying Relationships are represented by dotted lines. Entities that have no identifying parents are shown with right corners, while the rest of entities have rounded corners.