What is the abbreviation for National institute standards technology?

Looking for the shorthand of National institute standards technology or how to abbreviate it? We have 5 shorthands for National institute standards technology.

NIST — National Institute of Standards and Technologies
NTIS — National Institute of Standards and Technology
NNIST — National Institute of Standards and Technology
NIST — National Institut of Standards and Technologies
NIST — National Institution of Standards and Technology