Don't use d/d.. In numismatic terminology this means D over D Repunched mint mark. If you are asking if it's a possible Doubled Die then you would use DDO which means Doubled Die Obverse It's DDD - Die Deterioration Doubling
Thanks, -1987 D/D rpm 3-, I was referring to possibly that which I saw in the Lincoln Center Resource concerning the D in the 1987 cents. Also, the 7 and the 8 look double I just can't take a good picture for the life of me.