At first, this project used the CC BY-SA license to better disseminate the concept of the project documents, and the most important purpose is the promotion of free software. But we regret to see that this part of the content has been deliberately deleted from some derivative documents(such as https://arch.icekylin.online), and the promotion of free software is defined as "overly ideologically focused" and "not focused on practicality". This is completely unacceptable to the project team, which is completely contrary to the original intention of the project. From this we changed the license to CC BY-NC-ND.