Operators of voluntary sales by public auction shall declare to the Conseil des maisons de vente, within thirty days of the date on which they occur, any changes in fact or in law likely to affect their ability to carry out the activity of voluntary sales of furniture by public auction, in particular their temporary or definitive cessation of activity as well as any change in the situation declared pursuant to Article R. 321-1. These declarations must be accompanied by the necessary supporting documents.