The meaning of a spell with white characters on a black background (last time I saw a spell with white characters on a black background, my friend said it was called "ghost flag"

Oh, generally speaking, this is written in white on a black background, and Yinshan school will use it more, because they usually invite Yin soldiers and Yin generals. Of course, there are other theories, such as five elements, black belongs to water and white belongs to gold, and fire can be restrained by spells with white characters on a black background. Special symbols are special and cannot be rigidly adhered to. You can trust me privately if you have any questions.