Tiering
Tiering means, as defined in 40 CFR 1508.28, an approach where Federal Agency applicants, NCPC on behalf of Non-Federal Agency applicants, or NCPC for its own projects initially consider the broad, general impacts of a proposed program, plan, policy, or large scale project - or at the early stage of a phased proposal - and then conduct subsequent narrower, decision focused reviews.
Source
1 CFR § 601.3
Scoping language
For purposes of this part, the following definitions shall apply: