What are the important forms of ancient calligraphy?

Pan Shouyu, a famous scholar calligrapher and the first person in Qilu Ou Kai, said: Calligraphy is a person's clothes and appearance, and it is a symbol of talent and grace. People in China want to write a good hand, just as well as people. Articles are in Chinese, and calligraphy is also in Chinese. Calligraphy is the art that best represents the spirit of the Chinese nation. Calligraphy is an art that is easy to learn but difficult to master. As a traditional art, inheritance is its distinctive feature. It requires pen and ink to have a source and words to have statutes, unlike modern art, which can "do whatever it wants". It is true that the established statutes sometimes impose hard restrictions on calligraphy, but first-class calligraphers all come out of the statutes, "wearing Han and Tang costumes and dancing the style of the times." Only in this way can we become a real calligrapher who does whatever he wants in life.