'Top' shorthand for topkick, nickname for a company first Sgt.
'506' refers to the 506th Inf (ABN), formerly the 506th PIR, an outfit I've been associated with on and off for over 30-odd years.
Top
__________________
You know it's going to be a good day when the stem and seatpost come right out.
(looking for a picture and not seeing it? Thank the Photobucket fiasco.PM me and I'll link it up.)