Guidelines for Writing English-Language Technical Documentation
http://www.intecom.org/index.php?option=com_docman&task=doc_download&gid=2&Itemid=38&lang=EN

Intecom
2005

Abstract:

In 1999 the member societies of INTECOM recognized there was a need to help technical writers in all countries who have to write English-language technical documentation for products that will be sold worldwide. If they are writing for an audience solely in the UK, the Scandinavian countries, Australia, New Zealand, and South Africa, then British style is appropriate. Similarly, if they are writing for an audience solely in North and South America, the Philippines, and many Asian countries, then US style is appropriate. But if they have to write a single set of documentation for use in all countries, then a difficult decision has to be made.