GB/T 39105-2020Consumer product traceability—Data element directory for traceability system (English PDF)

3.1 Data element

4.3 Data format

In the data format of data elements in this standard, the meanings of the characters used are as follows: a = alphabetic character n = numeric character an = alphanumeric characters m (m is a natural number) = m characters of fixed length..ul = text of indeterminate length..p,q (p,q are all natural numbers) = the longest p numeric characters, q digits after the decimal point.. = From the minimum length to the maximum length, wherein the minimum length is appended to the front and the maximum length is appended to the back YYYYMMDDhhmmss = "YYYY" means the year, "MM" means the month, "DD" means the date, "hh" means the hour, "mm" means the minute, "ss" means the second, which can be combined according to the actual situation.

Example 1: an5(aannn) means 5 alphanumeric characters of fixed length, wherein the first 2 are alphabetic characters, the last three are numeric characters.

Example 2: n..17,2 means up to 17 numeric characters, with two digits after the decimal point.

Example 3: an3..8 represents an alphanumeric character of variable length with a maximum length of 8 and a minimum length of 3.

7.1 Usage of data element

Including direct use and derived use:

- Direct use: It may directly use the data element to carry out the design of the database or information exchange format;

- Derived use: Enterprises and (or) related organizations of different product categories can limit data elements and generate new data elements according to the characteristics of products and technological processes.

Compared with the original data element, the derived data element shall not appear contradictory in the definition, data type, data format, value range and other attributes. For example, "production date" is derived from the data element "date".

7.2 Extension of data element

The data element can be extended according to different consumer product categories and technological process characteristics. The representation of extended data elements shall comply with the provisions of Chapter 4, allowing more stringent restrictions on the attributes of data elements. For example, attributes that are optional in this standard may be mandatory after extension. […]