Standard

Standards are written by committees — of national bodies, international organisations or industry societies — through a consensus process, and they exist so that the same technical question does not have to be answered from first principles on every project. A standard for pipe defines the pipe once; every specification thereafter can simply cite it.

By nature a standard is voluntary. It acquires force through two doors: a law or regulation that incorporates it, or a contract or specification that cites it — after which "voluntary" is a description of its origin, not of anyone's obligations. A standard is also a dated object: it exists in editions, with amendments and corrections layered on, and a claim of compliance means little without the edition attached.

The everyday failure is treating a standard's name as sufficient identification. Two parties both "complying with the standard" while holding different editions are complying with different documents — and the differences between editions are precisely the clauses somebody thought worth changing.