Light Frame Infrastructure Series — Volume 23 (LFIS-23)Verification Semantics and Dual-Level Evaluation of LFCT Observational Regimes This addendum clarifies how observational tests of Light Frame Cadence Theory (LFCT) are to be interpreted and evaluated. It introduces a formal two-level verification structure distinguishing constraint-level predictions from observational-level statistical tests, resolving ambiguity that has arisen in the interpretation of several published LFCT regimes. LFIS-23 introduces no new physics, equations, data, or empirical claims. All previously published LFCT results remain unchanged. This volume defines verification semantics only. At the constraint level, LFCT yields exact, structural predictions derived from cadence and representability constraints. These predictions are formally falsifiable. At the observational level, empirical tests are statistical instantiations of those constraints and must be evaluated for consistency rather than exact equality. Using this framework, LFIS-23 resolves the classification of Regime 9 (cosmological distance–redshift drift in supernova observations), establishing that the global drift parameter κ is constrained to κ = 0 by LFCT’s Global Drift Cancellation constraint (C56, as defined in LFIS-11). The corresponding observational test is therefore a quantitative prediction evaluated statistically, not a descriptive consistency check. The volume also clarifies the current status of Regime 2 (dwarf spheroidal systems), explaining why no canonical numerical exponent is declared at present and why exploratory fits in that regime must not be promoted to predictions absent explicit declaration. Conditions under which Regime 2 could be promoted to a quantitative test in future work are explicitly stated. Finally, LFIS-23 establishes formal classification rules for LFCT observational regimes, including explicit prohibitions against implicit parameter fitting and post-hoc promotion of exploratory regressions. These rules are intended to guide both human reviewers and automated verification tools. This document is additive and canonical. It serves as a permanent reference for interpreting LFCT verification claims across the LFIS series and associated observational test suites, including the LFCT 9-Regime Observational Test Suite and any future verification suites developed under the same framework.