Custom Tab

This area stores controls you’ve already created and customized so you can re-use them. Maybe you’ve created a dropdown list with your ten branch offices, for example. To add a customized control to this area, drag it from the form you’re working on and drop it over the shaded area that says “Custom.” (You can’t drag the control into the area beneath this.) The name you see in the Custom Area will be the control’s label; if you can't see the entire label, hover over the control to see the full name.

...