Sounds like a reward and attribution offered by PCGS for the first 1976-D Kennedy halves submitted for grading. PCGS recently had a similar program for the first examples of "W" mint marked Washington quarters.
Without an image I couldn't say for sure what it is. Could be a coin slabbed by PCGS to be given away at a coin show that had a youth "Treasure Hunt". Kids would go to around to participating dealers and answers questions. One of the rewards would be a slabbed coin that "commemorated" the treasure hunt.