In some countries, practical guidance on selection procedures encourages domestic contracting authorities to limit the prospective proposals to the lowest possible number sufficient to ensure meaningful competition (for example, three or four).
在有些国家，关于筛选程序的实用指南鼓励本国订约当局尽可能减少预期的投标书数量，以足可确保有意义的竞争为限（例如三份或四份）。