In addition to the form designer, there is also Form layout in the Configure menu when right-clicking the header. This allows you to modify nearly everything that you changed through the form designer, though it isn't as user-friendly. In exchange for that lack of user-friendliness though, the trade-off is that you can easily add derived fields based on related records in reference type records.

Let's walk through an example, so you can see what I'm referring to:

1. Right-click in the header of the Virtual War Room form again, and go to Configure | Form Layout.
2. Scroll down to the Major incident field that we created. It should be highlighted in green, and have a little [+] next to it. This indicates that it is a Reference field.
3. Click on Major incident to highlight it, and a new icon will appear before the other two buttons, in-between the Available and Selected lists. Clicking this button allows you to dot-walk to access the fields on the Incident table, and add them to our Major incident table.
4. After clicking that icon, you should see a new list of options in the Available box on the left. From that list, double-click on Short description.
5. Use the arrows to the right of the Selected box to move the two new fields up or down so that the Major incident. Short description field is right before Work notes.
6. Click the blue Save button on the form layout window, and you should be returned to the form.

Now you've got the Short description field from the Incident table (via the Major incident field) displayed on your virtual war room form. If you want to see this value populated, just click the magnifying glass icon to the right of the Major incident field, and select any incident from the list that pops up. The Short description will populate automatically, displaying the short description from the incident you've selected!