One side effect of the use of both Roman numerals and uppercase letters in all of these styles of outlining is that in most alphabets, "I." may be an item at both the top (A-head) and second (B-head) levels. This is usually not problematic because lower level items are usually referred to hierarchically. For example, the third sub-sub-item of the fourth sub-item of the second item is item II. D. 3. So, the ninth sub-item (letter-I) of the first item (Roman-I) is item I. I., and only the top level one is item I.
