In Chapter 2, it is pointed out that standards are generally written to achieve safety and reliability, to reduce cost and increase flexibility, to promote business, and to help society function. A well written standard will accomplish these goals effectively. A poorly written one will accomplish them less well, and may even impede them. This chapter identifies those characteristics that make for an effective standard. These characteristics help in selection when there is a choice of standards, development when a new standard is needed, and effectively supplementing an existing standard with proper text in a specification, statement of work, or other contract documents.