2. Type: There is no fixed or standard classification, but there are probably the following kinds of bibliographic classification.
① Compilation purpose and social function: registered catalogue (national bibliography), subject notification catalogue, recommended catalogue, special subject and special subject catalogue (China agricultural bibliography), bibliography guide (national library bibliography) and published bibliography;
② literature collection scope: collection catalogue and scope.
③ Contents of documents listed in the catalogue: comprehensive catalogue, special catalogue, personal writings catalogue and local literature catalogue;
④ Reflect the types of documents contained in the catalogue: book catalogue, periodical catalogue, map catalogue, patent catalogue and standard catalogue;
⑤ Publication time and catalogue compilation time of the included documents: current catalogue, retrospective catalogue and preview catalogue;
⑥ Arrangement of collected documents: classified catalogue and alphabetical catalogue;
⑦ Degree of disclosure of documents: title, abstract, abstract, etc.
3. Function: Instruct people to read and study, and indicate which books need to be read first and which books can be read later, and also tell you which books need to be read carefully and which books only need to be browsed. It can also record all the books in a country; Works reflecting the lives of celebrities; What books can be reported on a certain subject; That is, books or something.
Function: excellent figures can reflect the general situation of an academic field in a certain period and have important reference value; Bibliography transmits catalogue information, reports comprehensive research results, introduces book contents, reflects publishing and collection, and provides reference books for circulation and custody; Numbers can indicate the reading path.