Many of these are the subject of extensive trade references and have been based on carefully conceived concepts. Many other designations are also well established and, by virtue of their long history of usage, have become very well known to the individuals and areas of commerce in which they are employed. Some confusion can be caused when they are used outside the usual sphere of influence. The administration of this system is based in North America. It has proved impossible to adopt it to a system suitable for other national and international preferences.
Similar considerations apply to other national systems.
1190 Pt 1, based on the element symbols and the descending order of magnitude of alloying elements. This system is easy to use by humans but can be unwieldy when used to describe complex alloys with many alloying elements. It can be difficult to sort and index using computer programs. It has, however, been widely adopted throughout Europe during the last 20 years or so as many countries have been adapting ISO Standards with modifications for use as national standards. It is also now common practice in European technical meetings for materials to be referred to by this compositional designation.