In Harry Potter and the Half-Blood Prince, Draco Malfoy uses a pair of enchanted coins to bypass the communication limits imposed on Hogwarts, thus managing to keep in contact with Madam Rosmerta, whom he had placed under the Imperius Curse. The coins grow hot when the numbers change to alert the members to look at their coins. Due to the coins being infused with a Protean Charm, once Harry Potter alters his, every coin changes to suit. On non-enchanted Galleons these serial numbers signify the goblin who cast the coin on the enchanted Galleons, the numbers represent the time and date of the next DA meeting. Like non-enchanted Galleons, the coins have numerals around the edge. In Harry Potter and the Order of the Phoenix, Hermione Granger creates fake, enchanted Galleons (wizard money) that are used for communication between members of Dumbledore's Army (DA).
