http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Safety requirements for turning centers and automatic, numerically controlled turning machines
secretariat and accredited standards developer: B11 Standards, Inc.
"Approved: 14 June 2002. Reaffirmed: 27 November 2012, American National Standards Institute."