"G" is the code of China Library's book classification, and different letters represent a book. G stands for cultural, scientific, educational and sports publications. G4 periodical means that the authors of this kind of periodical are mainly for educators, and the service targets are all educators. Publications marked with G4 represent educational publications.

Educational periodicals are professional educational media with the main mission of serving education and the healthy growth of teenagers. They have distinct educational dominance, distinct regional characteristics and distinct industry dependence, and play a special responsibility and communication function different from other newspapers and periodicals. Periodical positioning means that periodical operators set goals for periodical management and service according to the needs of readers and the situation of competitors in the market, shape the image, and convey this image to readers, so that readers can understand and recognize it, thus establishing the position of periodicals in readers' minds.

The periodical positioning mechanism should include clear positioning objectives, detailed positioning explanations and effective positioning effects.