Admissible Identity Drift in the Standard model

This paper analyzes the conditions under which identity drift is admissible within the Standard Model when standing preservation, admissibility, and redescription stability are enforced. The analysis is eliminative: it shows that while limited identity drift is structurally permitted under admissible redescription, unrestricted or continuous drift collapses equivalence classes required for standing. Identity is treated as a standing-preserving classification rather than a fixed ontic label. The paper demonstrates that admissible identity drift is tightly constrained by compositional stability and closure: identities may transform only along paths that preserve distinguishability under interaction. Attempts to extend identity drift beyond these bounds are shown to require illicit scope transport, deferred admissibility, or post-selection. The paper introduces no new primitives and provides no mechanisms or dynamics. Its contribution is boundary-setting: it clarifies which forms of identity drift are admissible within Standard Model bookkeeping and why identity cannot be treated as arbitrarily fluid without violating standing conservation.