Use of Fulfillment Item Code in Product Configuration

Hi All,

I want to know the Use of Fulfillment Item Code in Internal Product - ISS Admin .

1) Its not shown on Applet , How its Populated ?

2)What is the use of this field?

3) After Exposing on Applet , its showing Pick Applet, where i can select the Records as described below.

If Product is having Product Class then I can Choose its Class.

If Product is having the Product Class and if the Product Class is having the Parent Class then I am able to choose Product Class. If Parent Product Class having Other Parent Class then I can able to select Product Class and Immediate Parent Class.