I accidentally discovered that I can transform my forms list into a tree. I dragged FORM1 onto FORM2 and oo/loBase changed FORMS into a folder with FORM1 as subordinate. Except it wiped out FORM2.

After some research, I see how to create a folder into which I can save form(s). As far as I can tell, this only works using the SAVE dialog box in CREATE FORM IN DESIGN VIEW I see no way to make this happen using the WIZARD.
Here's how:
1. Click on CREATE FORM IN DESIGN VIEW and then SAVE (or use FILE.SAVE) before creating/saving your form.
2. The SAVE dialog box displays.
3. Click on the CREATE NEW DIRECTORY icon, 2nd from the right at top of the dialog.
4. Another dialog box opens, allowing you to enter FOLDER NAME.
5. Then OK. On return to the SAVE dialog box, you'll now see the new folder.
6. Then create a form, also in CREATE FORM IN DESIGN VIEW.
7. Then Save, clicking on the new FOLDER in the dialog box. Name your form,then SAVE.
8. On return to the FORMS pane, you'll see the new folder with a '+' icon indicating that it holds the new form.
This is an unexpected and mighty feature. I can now create an application with many forms and organize the forms in a manageable way. I checked documentation and the forum and did not find this feature defined, so I thought I'd share.
Enjoy!
Buz