函和请示、报告均为公文的一种类别。报告是向上级机关汇报工作、反映情况的公文;请示是下级机关请求指示的公文;函是机关之间商洽工作、询问和答复问题的公文。使用函的机关之间,是平行的或不相隶属的,它不具有指挥或指示的作用。按照《国家行政机关公文处理办法》的规定,向业务主管部门请求批准应该用函。根据内容和用途不同,函可以分为商洽函(用于平行的、不相隶属的机关、单位之间 Letters and requests, the report is a type of document. The report is a document that reports to the higher authority and reflects the situation. Please indicate the official document requested by the lower authority. The letter is the official document of the work of the authorities for consultation, questioning and answering the questions. The agencies that use letters are either parallel or non-affiliated and do not have the role of a conductor or direction. In accordance with the provisions of the Measures for the Administration of Official Documents in State Administrations, a letter of approval should be submitted to the competent department of commerce for approval. According to the different contents and uses, letters can be divided into negotiation letters (for parallel, non-affiliated agencies, between units