Ok, I know what's going on now. The transitional variety on the 88 P and 88 D are the designer's initials at the bottom right of the Memorial. For some strange reason they call it the wide AM. It has nothing to do with the AM. Look up RDV-005 and 006 and you'll see the variety.
I’m out of town visiting grandchildren, so I have not been back to this thread until today. Much to my personal embarrassment, I find that I am partially wrong in my opinion and assessment of this coin. Several online guides for Lincoln cents list this as a wide AM. Others correctly identify it through the variation of designer initials.
It is, therefore, quite understandable that the original poster zeroed in on the wide AM aspect of the coin, and not the variety of the initials. Thank you, Enamel7, for the information.
I know this is a month old, but I went back and read my response and realized I made an error. I should have said the reverse design changed in 1989 and again in 1993.