I had a form in a requests database. The rich text field needed to be large to take up space in the form and to show it was important. I also had to make sure it was filled in before saving.

The default value of the rich text field called Body was:

@NewLine+@NewLine+@Repeat(" ";175)

The code to make sure it was filled in was stored in the QuerySave of the form.

If Len(source.fieldgettext("Body"))=179 Then
  Messagebox "Please fill the ""Description"" field."
  Print "Description field must be filled in."
  continue=False
End If