What is the unit code of the employee basic medical insurance registration form?

It's the number filed with the Human Resources and Social Security Bureau.

Coding is the process of converting information from one form or format to another, also known as code abbreviation coding of computer programming language. Encode characters, numbers or other objects into numbers by a predetermined method, or convert information and data into prescribed electric pulse signals. Coding is widely used in computer, television, remote control and communication fields. Coding is the process of converting information from one form or format to another. Decoding is the reverse process of coding.