What is what does delivery report not requested mean?

Delivery report not requested means that the sender of the message did not ask for a confirmation or acknowledgement that the message was received by the recipient's device and successfully delivered to the intended destination. In other words, the sender did not request a delivery report for that particular message. This is commonly used when sending less important or less critical messages where the sender does not require a confirmation of receipt. However, it is important to note that if the recipient's device has the option enabled to automatically send read receipts or delivery reports, the sender may still receive a notification without having requested one.