What is the symbolism of Day's pendant?

The night he attempts to steal plague vaccines from the hospital, Day loses his pendant necklace. The military officers investigating Metias’s death later find this necklace and eventually June uses the necklace to identify Day. At first it seems the pendant is simply a trinket Day’s father gave to him and hence only has sentimental value. A flashback to Day’s childhood, however, reveals that the pendant is actually a disguised piece of currency from the former United States of America. We are not told much about the coin’s significance, only that it is proof the United States existed and that it is dangerous for the Wings to have it. Rather than get rid of it, the Wings decide to hide the pendant in plain sight by disguising it and giving it to Day to wear. The pendant can be seen as symbolic of Day himself. Despite being a notorious enemy to the Republic government, he hides himself in plain sight with disguises and subterfuge. Furthermore, similar to the pendant, it is dangerous for Day to be seen with his family.