The author of the Kitzur Shulchan Aruch gives a sample deed of sale which he used for mechiras chametz. (end of chapter 114)  In this deed he gives a detailed list of the chametz items to be sold, the sale value of each item and its precise location in the house of the seller. In contrast, I have seen such deeds in which there is barely room for the members of the community to write just their name and address!