The document number consists of the word, year and serial number of the issuing authority. Agency substitution generally includes two levels. The first level is for the issuing authority, and the second level is for the sponsoring department of the issuing authority. For example, the official characters of the document of the Ministry of Railways are "Tieban" and "Tiecai", where Tieban stands for the Ministry of Railways, and "Banban" and "Caicai" stand for the office department and financial department of the Ministry of Railways that sponsored the document. It is very important to know the nature of the organization, especially who is the sponsor of the document, so as to process, query, save and archive the document more accurately. For example, in the State Council, there are "Guo Fa" and "Guo Han", with "Guo" representing the State Council, and "Fa" and "Han" representing "the State Council Document" and "the State Council Letter". Some document institutions have as many as seven or eight words or more, which may be at different levels, but it is better to simplify them as much as possible.

The full name of the year should be used, and it cannot be simplified. For example, "87" and "93" are all marked wrong. The year should be enclosed in hexagonal brackets. Note that hexagonal brackets are not brackets in mathematical formulas, because when quoting official documents, the document number after the title should be enclosed in brackets "()". If the year is enclosed in brackets, it violates the principle that high-level symbols should not be included in low-level symbols. Therefore, it is called "hexagonal bracket" because it is different from brackets in mathematics. In addition, their shapes are slightly different. Some documents enclose the year in brackets, and then use hexagonal brackets according to the provisions of this standard.

The serial number is the serial number of the document. Generally, it is compiled in the form of documents, that is, which department sponsored it. As long as the forms are the same, they should be numbered sequentially. It is a complicated method for some organs to divide and number according to the contents of the sponsoring department or documents. This standard stipulates that the serial number should not be filled with imaginary numbers, and function words such as "the first" (some units add "the word") should not be added. The main purpose is to pay attention to practicality and minimize the number of words in official documents.

For the position of the document number, this standard stipulates that two lines should be left blank below the document number, and a red reverse line with the same width as the plate center should be printed 4mm below the document number. It is clear that the distance between the document number and the red reverse line is three lines, and the document number should be marked on the third line, and it should not be close to the red reverse line, leaving a distance of about 4mm (as long as the red reverse line is not attached to the actual grip). The document size should be in the middle.