What does China Mobile mean by "ktxy"?

Look at the prefix of this letter, it should be to open some services, which belongs to the mobile short message instruction. For example, when opening some services, it will start with KTV letters. You can try to send a letter to see what services have been opened. Double confirmation of SMS instruction of mobile service. After sending the letter, you will be asked to reply to the corresponding confirmation information again before you can open the business of this instruction.