Naming Technique of the Night - Chapter 113 - : 113, Meeting gift

... ll stone monuments with inscriptions like “18, 223,” “18, 224,” appeared along the roadside.

They were like boundary markers.

Uncle Li Dong explained to Qing Chen that they were still within the territory of City 18, and the subsequent “223” marking was a landmark for easy recognition of the location.

As the sun began to set in the west, Qin Cheng suddenly said over the walkie-talkie, “It’s getting late. We will soon reach the iron net entrance, get ready to camp.”