A mnemonic dominic system is a way of remembering and organizing information. It works by using images, rhymes, words and colors to form a mental picture of something, or a "memory map." For example, if you wanted to remember the colors of the rainbow (red, orange, yellow, green, blue, indigo and violet), you might create a picture of a rainbow in your mind and imagine each color in a different part of it. This might help you to remember the colors more easily.