1. Xuzhou, formerly known as "Guo Xu", is located in the northernmost part of Jiangsu Province, adjacent to Anhui Province. Geographically, Xuzhou is located in northern Jiangsu. "Lao" usually refers to the address of the elderly in the dialect, or it can refer to the ancient and primitive place. Therefore, the naming of Xuzhou after "Lao Xu" may be a description of its geographical location and long history.
2. "Thirteen Taibao" originally referred to thirteen sons of Li Keyong, and was appointed as Taibao in the late Tang Dynasty. Because these thirteen sons are all very capable, and none of them is poor in ability, "Thirteen Pacific Insurance" has become a word referring to capable people. Xuzhou is one of the thirteen prefecture-level cities in China, a comprehensive transportation hub in Jiangsu Province and a central city in Huaihai Economic Zone, so it is called "Lao Xu", which shows its ability and status as a central city.
To sum up, the reason why Xuzhou is called Lao Xu is not only related to its geographical location and long history, but also reflects its central position and importance in Jiangsu Province and its surrounding areas.