by all of these switches you can control some field behavior. As you can see in attached image, the meaning of these shortcuts is following:
PK - Primary Key. By this checkbox you can control if selected field will be exported as a primary key
FK - Foreign Key. This checbox is read-only and symbolizes that the field is used by any association as owner field
AI - Auto Increment. This checkbox sets if the specified field will be marked as Auto-Increment. It's useful only for primary keys.
NN - Not NULL. By this checkbox you tell ORM Designer to export NotNull constraint to this field.
UQ - Unique. Similar to NotNull, by this checkbox you tell ORM Designer to export a Unique constraint.