National CAD Standard is voluntary, however adopting companies and agencies can require its use by their associates. National CAD Standard The National CAD Standard (NCS) is a collaborative effort in the United States among computer-aided design (CAD) and building information modeling (BIM) users. Its goal is to create a unified approach to the creation of building design data. Development of the NCS is open to all building professionals in a collaborative process led by the buildingSMART Alliance. The NCS is composed of CAD layer guidelines from the American Institute of Architects, uniform drawing system modules from the Construction Specifications Institute, and BIM implementation
Recursive acronym existing ordinary acronym is given a new explanation of what the letters stand for, or a name is turned into an acronym by giving the letters an explanation of what they stand for, in each case with the first letter standing recursively for the whole acronym. In computing, an early tradition in the hacker community (especially at MIT) was to choose acronyms and abbreviations that referred humorously to themselves or to other abbreviations. Perhaps the earliest example in this context, from 1960 the backronym "Mash Until No Good" was created to describe Mung, and a while after it was revised