What does the second sister mean in 12345?

Clean in place. The 12345 project belongs to Guizhou Xu Dong Construction Engineering Consulting Co., Ltd. According to the query of official website of Guizhou Xu Dong Construction Engineering Consulting Co., Ltd., the two cleanings in the 12345 project mean that the cleanings are in place. The main business includes: engineering bidding agent Grade A: engineering construction project survey, etc.