High Impact System

An information system in which at least one security objective (i.e., confidentiality, integrity, or availability) is assigned a FIPS Publication 199 potential impact value of high. 

See the following under High-Impact System for more information: 

NIST SP 800-53 Rev. 4(FIPS 200).
FIPS 200.
NIST SP 800-18 Rev. 1.
NIST SP 800-37 Rev. 1(FIPS 200).
NIST SP 800-60 Vol. 1 Rev. 1(FIPS 200).
NIST SP 800-60 Vol. 2 Rev. 1(FIPS 200).
NIST SP 800-137(FIPS 200).
 
An information system in which at least one security objective (i.e., confidentiality, integrity, or availability) is assigned a FIPS PUB 199 potential impact value of high. Note: For National Security Systems, CNSSI No. 1253 does not adopt this FIPS PUB 200 high water mark across security objectives. 

See  CNSSI 4009-2015 (FIPS 200) for more information.