While in a Sherlock Holmes holoprogram, Data pointed out von Ormstein's snuff box, placed on the mantelpiece in Sherlock Holmes' apartment. He also noted that all objects on the mantlepiece had significance to Holmes. (TNG: "Elementary, Dear Data")
The king of Bohemia
The character was from the story A Scandal in Bohemia, where he is said to be the King of Bohemia. Sherlock Holmes having received a snuff box as thanks for his services in that story is mentioned in A Case of Identity. However, in the holoprogram Data showcases von Ormstein's snuff box, and is then presented with the case shortly thereafter. Since the first mention only calls the character von Ormstein, and the second only refers to the king of Bohemia, the two might actually be considered different characters within the world of Star Trek.
