Tattoos were also frowned upon in my time in Group. A number of the older airborne vets had tattoos left over from their time in the various regiments, but tattoos were seen as indelibly identifiable marks and assignment limiting.
FWIW - tattoos, piercings, and the like are considered to be socially lower class amongst our family - whether anyone else thinks they are or not. Be that as it may, our middle son, who is really attuned to our Scots heritage, had our family shield (Clan Hay) placed on his left bicep. He worried about my reaction and was surprised when I told him why I didn't think it was a great idea (marking, > incidence of latent hep-C, views of others, etc) but that it was his problem, not mine, and he was the one who had to live with it. I was not thrilled that he had done that, but he's over 18 and it could have been worse...it could have been a globe and anchor or the like.
MOO...and not tattooed.
Richard's $.02
PS - as far as the Nazis and tattoo souvenirs - Expat was thinking of Ilse Koch, the commandant's wife at Buchenwald near Weimar (Bitch of Buchenwald) who was convicted in the post-war trials. Even by the accepted standards of those incomprehensible camps, Buchenwald was seen amongst the RFSS and WVHA-Amt D staffs as being OOC and the practice of such souvenirs was not encouraged.