Psychelian designation code

The Psychelian designation code (abbreviated as PDC) is a code given to each Psyche upon his or her "day of emergence" as a young Psyche in the EMPATH: The Luckiest Smurf story series. The code usually consists of a four-digit number followed by a letter that is imprinted on the back of each Psyche's head in the form of a brand. This code remains within the Psyche's memory for life and cannot be erased, though it can be forgotten over time.

Empath, the only Smurf who was raised among the Psyches as one of them, was given a designation code upon his "day of emergence", which is 1137-K.