These two stone tablets have high cultural value. In the tenth year of Jian 'an (205), Cao Cao banned the erection of tombstones on the grounds of "furious". In the fourth year of Xianning (278), Sima Yan, Emperor Wu of the Jin Dynasty, wrote: "Monuments show private beauty, glory and hypocrisy, and nothing more, they are forbidden." Monuments were still strictly forbidden in the Southern Dynasties, so there were few stone carvings, and it was not until after the Northern Wei Dynasty that the monument was lifted. Therefore, in the history of calligraphy in China, there is a unique phenomenon that there are fewer South Monuments (North Korea) and more North Monuments (North Korea). However, these two stone tablets, especially the "Gui Long Yan Tablet" which was strictly prohibited during the Liu and Song Dynasties in the Southern Dynasties, became the only stone tablets left in this period. Only in this way, it is appropriate for future generations to call these two monuments "the treasures of the South Monument".
Yan Longbei says that he is a descendant of Zhuan Xu, Zhu Rong, Ban Biao and Ban Gu. At the end of the Eastern Han Dynasty, Ban was given the title of "Yao fief" (according to legend, in Dingxiang, Xinxian County, Shanxi Province), taking Yao as his surname. With the rise and fall of the clan, he moved southward, passed through Yong and Shu, namely Hubei and Sichuan, and imitated into Yunnan. Cuan clan ruled Yunnan for hundreds of years and for a long time. Even after the Wei and Jin Dynasties, the indigenous people in Yunnan were collectively referred to as "Yi people", thus replacing the once popular title of "Yi" (such as Sima Qian's Historical Records and Biography of Southwest Yi). Interestingly, in the late period of cuan clan's rule, the so-called "East Yi" and "West Yi" national phenomena really appeared. Due to the long-term rule of cuan clan, surnames became surnames, which is a subject worthy of serious study by historians and anthropologists.
Although Ji Longyan's epitaph records that he held four official positions, his main official position "secretariat" is not recorded in the historical records. The reason was that the imperial court was unable to govern Yunnan at that time, and "giving history from a distance to secretariat" was only nominal rule. The "secretariat of history" became the official post granted by cuan clan's imperial clan, which was inherited by his grandparents and grandchildren, and was a veritable "local official". From Zhuge Liang's support for Nanzhong's Jie Jun to the hereditary inheritance of cuan clan local officials' grandparents and grandchildren, it can be regarded as the origin of the Tusi system in Yunnan in the Yuan Dynasty. Obviously, it can not be ignored to study the Tusi system in Yunnan and the historical phenomenon of cuan clan Tugong's ancestral inheritance.