Received an answer today!
Hi Andreas, sorry for not getting back to you earlier. I did receive your email as well. Thanx for spotting that. The / sign should not be there. It should read Dm sus 4. The sus4 is actually the melody note over that chord. I had some issues with the person that copied my work using the finale software program for the book production. Thanx for bringing it to my attention. Your the first one to spot a rare imperfection in the music. There may be other imperfections but have not been brought to my attention. Overall the transcriptions are very close to 100% accurate. Sorry to put you through this. I remember going through this tune with Tommy and the chords were as he saw them. Hope this all helps. I’m glad your enjoying the book!
Happy Picking,
Peter Pik
So it was just some issue with the notation software. Case solved!