Allow for numbered/lettered lists in text fields which display all levels and sub-levels appropriate for that list item. Include the ability to independently chose a number/lettering system for each level.
For example, see below and the attached document showing how word handles this item:
1. Text
1.A. Text
1.B. Text
1.B.1 Text
1.B.1.a Text
1.B.2 Text
1.C. Text
2. Text
2.A. Text
2.B. Text
2.C. Text
2.C.1. Text
2.C.1.a. Text
2.C.1.a.i. Text
2.C.1.a.ii. Text
2.C.2. Text
