http://www.csemag.com/single-article/soft-and-hard-metric-conversions/8203d3c07c36773c13673e99ca608165.html
Quote:Soft metric is not a mix of imperial and metric measurements, and
the Dept. of Defense does not recommend it for engineering drawings.
They would be better off forbidding it than
What they should do is use the current SI-10 definitions of conversion vs.
substitution. The old Hard vs. Soft was very confusing and
B.7 Conversion versus substitution
Transitioning from traditional inch-pound units to SI requires changing
quantity values from one system to another. This can
www.worldmetrologyday.org
http://www.ebmag.com/Events/world-metrology-day-2014-measurements-and-the-global-energy-challengehttp://www.ebmag.com/Events/world-metrology-day-2014-measurements-and-the-global-energy-challenge
http://www.worldmetrologyday.org/events.html