In the bidding document. There are specific explanations. There will generally be clear instructions in the front schedule of the bidding document, or there will be a section for submitting bid documents before the contract part of the bidding document. At least one of these two places will raise specific requirements. Nowadays, it is generally required to bind on the left side. There are also bindings with black or white hot melt strips (with several holes) and so on. Binding on the left side is also divided into nail binding and nailless perfect binding.

Tender documents generally require kraft paper packaging, which means that the bid documents must be sub-contracted or combined according to the requirements of the bidding documents, wrapped in kraft paper and affixed with a seal. The new version of the bidding document shall be stamped with the official seal. The old version of the bidding document has an official seal on the inside and a legal person seal on the outside.