There are multiple definitions:

1. National Institute of Standards and Technology(English)

   • NSF, ALFUS, SAE, UMS, NREL, RIT
   • Organizations (documentation), Standards, Medical technology (assessment)
   • https://doi.org…OC.2014.2298437
   • https://doi.org…T.sp.1011-I-2.0

2. National Institute of Science and Technology(English)

   • formerly NBS
   • NBS
   • Organizations (documentation), Organizations (scientific)