The clan sign cast inside the foot of each gu may be read as tie zhu. The graph tie consists of a pair of ears and the graph zhu is in the shape of bamboo branches. Both graphs are known as individual clan signs and are combined as a composite clan sign on the present gu.
The gu is the quintessential vessel type in Shang ritual paraphernalia, and together with a jue or jiao it forms the basic wine vessel set for aristocrats to perform rites. The higher the rank of the aristocrat, the greater number of gu-jue/jiao vessel sets. A set of ten fanggu and ten jiao, bearing Ya Zhi clan signs, found in Guojiazhuang M160 at Anyang city, is illustrated by Yue Hongbin, ed., Ritual Bronzes Recently Excavated in Yinxu, Kunming, 2008, pp. 240-41, no. 119. It is, however, very rare to find pairs or sets of gu identifiable by their inscriptions.
Another rare feature of the present pair of gu is the extension of the flanges over the mouth rim. This feature usually appears on vessel types of the highest status, such as the aforementioned Ya Zhi fanggu, and the fangzun from the Fujita Museum, which was sold at Christie’s New York, 15 March 2017, lot 523. Only a few gu with flanges extending over the mouth rim appear to be published: one similar gu with a Zi Wei clan sign, found in M2508 in the Western district of Anyang city, is illustrated in Shang Ritual Bronzes in the National Palace Museum Collection, Taipei, 1998, p.291, fig. 43:2; and another similar gu in the Freer Gallery is illustrated by John Alexander Pope and Rutherford J. Gettens in The Freer Chinese Bronzes, vol. 1, Washington D.C., 1967, pp. 68-73, no. 10. (fig. 1) On these examples, the flanges not only emphasize the layout of the design but also serve to enhance the elegant form and sense of large size.