Origin Of Moon And Star In Muslim Countries Flag
It has no religious significance. The most probable reason seems to using this symbol to distinguish from the Cross used by Christians, specially by the Ottoman Empire and then this tradition passed down to Muslims. Following articles might be of some help in this regard: https://islamqa.info/en/answers/1528/taking-the-crescent-as-a-symbol https://islamqa.org/hanafi/darululoomtt/148977/what-is-the-ruling-on-the-moon-and-star-symbol/