What does this necklace symbolize?

It reminds me of a Pastor's illustration. A woman bought a pendant with Thai letters and some numbers. It was her favorite piece and she wore it everywhere. One day she met a man from Thailand and she showed him her pendant telling him how much she loved it and never took it off. She wanted to know what it meant and he refused at first, but when she pressed him he relented and told her it was a prostitutes license. She wore it without knowing what it meant. Many people, Christians included, wear crosses on them and they do not really understand what it means.