Greetings Huawei251, I am so glad that you have decided to test MediaWiki here with us. While I want you to know that you are free to test editing the system messages, please speedily revert them as soon as you are done as it can be pretty confusing to a new user when the rest of the wiki is in English and the new page message is in another language :P. Just to be clear, you have not done anything wrong but I just want you to make sure you are extra careful when editing in those areas. Thanks!