Stolpersteine, Spitalgasse.

Same street as the last entry and by chance I spotted this shot in front of a shop I never go into. The rain had driven me towards it when I saw the two names. Stolpern means to stumble and stolperstein may be translated as stumbling block. According to Wikipedia "Before the Shoah, it used to be the custom in Germany for Non-Jews to say, when they stumbled over a protruding stone: "There must be a Jew buried here." The 20,000th stone was put in place in the year 2009 and they are found all over Germany and beyond.
The Bissbergs had a shop in Spitalgasse in Coburg and were arrested by the Nazis in 1933. It's not known what happened to Moritz as the question marks indicate.
I presume the white mark is chewing gum! ( but will have to check.)