History textbooks in contemporary democracies have often been exposed to censorship and other forms of interference. This article presents the idea of a classification of these forms as a novel way to contemplate the ambivalent relationship between democratic authority and historical instruction. The model primarily distinguishes official forms of textbook interference from private forms of interference. I will discuss three forms of official interference and three forms of private interference to demonstrate the potential of the approach. More forms are conceivable, as the classification model is exhaustive nor finite. Forms of interference often coincided or overlapped each other. The model primarily seeks to stimulate the development and use of concepts capable to bring case analysis beyond crude dichotomies such as that formed by censorship and freedom of information. The deliberate use of interference terminology enhances reflection on the status of textbook history as both object and product of multiple forms of interference in democratic societies.