From the land of “Herr Doktor Doktor” via Language Log:
…Ian Thomas Baldwin, who holds a PhD from Cornell, and now serves as researcher at the Max Planck Institute for Chemical Ecology in Jena… [had] been accused of “title abuse” by the German police under a little-known Nazi-era law that specifies that only people who hold PhDs or medical degrees from German universities are permitted to be called “Dr.” [But] persons with a PhD from an accredited US institution can now use Dr. in Germany without jeopardy. As I understand this, however, PhDs from Japan, Canada, and other countries are still banned from calling themselves Doctor. [emphasis mine]
Even when we had Grade 13?