A Specification Correspondence Review is Plumb's Tier 3 review: Tier 1 plus a comparison of the shop drawings against the project specification the customer supplies, the client's written requirements for materials, finishes, fabrication methods, testing and documentation. The question it answers is whether what the drawings show corresponds to what the specification says, requirement by requirement.
The specification is parsed once, for $200, into a spec library entry that is reused on every later package for that client. Each sheet is then reviewed against it for $0.15 per sheet, on the plan's next invoice. Specification findings are numbered in their own series, S1, S2 and so on, and each one cites the spec section, quotes the requirement, then states what the drawing shows. A compliance matrix lists every parsed requirement with a status, including the ones the drawings are silent on and the ones that could not be confirmed.
Tier 3 reports correspondence, not compliance. It does not decide whether the contract has been met, and it does not include Tier 2's submittal checks.
How Plumb uses the term
Tier 3 is for spec-driven contracts, themed entertainment above all, and is available on the Shop and Studio plans. See /pricing and the themed entertainment page.