Although the subject of the article is the current US defense chief, it mentions handout coins several times. There is no mention of the term "challenge coin" in the article. https://www.nbcbayarea.com/news/pol...g-War-Zone-Troops-for-Holidays-467153343.html Defense Secretary Mattis Nixes Holiday Tradition of Visiting US Troops in War Zones Lolita C. Baldor and Robert Burns of Associated Press Like his predecessor, Gates ended his troop talks with the traditional lineup for handshakes, photos and the much-desired commemorative coin. The coins — different for each secretary or military commander and emblazoned with their names or unit designs — are ceremonial gifts that young service members embrace. Many collect them or use them to get free drinks in bars. One game stipulates the service member with the highest-ranking coin wins. Secretaries Leon Panetta, Chuck Hagel and Ash Carter followed suit, trailed by a military aide carrying the coins that they often handed out to hundreds after each event. Mattis rarely gives public troop talks, in any season. Usually he meets privately with small groups of service members. And he has declined to hand out coins. Of course, I would have rather gotten a coin from Hopalong Cassidy. Hopalong Cassidy (William Boyd) hands out coins.