The use of books to influence public opinion in favour of a political ideal or government policy, whether nationally or internationally, may include art and photographic, racist and religious propaganda, government and official information, all of which may be misleading, inaccurate, idealistic, moralistic or unrelated to its context. Most significantly book propaganda includes textbook indoctrination which affects the most susceptible members of society and young people, and which may be the only 'factual' information available for studies. Other versions may be censored. Book propaganda sharpens international and political conflict and if it is subversive it may be severely repressed. The effects of official book propaganda may be less obviously visible, but it contributes considerably to feelings of nationalism, prejudice, discrimination, elitism and social conflict, to political apathy, and conformism.