Tiering
Tiering refers to the coverage of general matters in broader environmental impact statements or environmental assessments (such as national program or policy statements) with subsequent narrower statements or environmental analyses (such as regional or basin-wide program statements or ultimately site-specific statements) incorporating by reference the general discussions and concentrating solely on the issues specific to the statement subsequently prepared.
Source
40 CFR § 1508.1
Scoping language
The following definitions apply to the regulations in this subchapter. Federal agencies shall use these terms uniformly throughout the Federal Government.