---
id: ADR-PFM-ELG-005
title: Published versions are immutable and a rollback is a new version
product_area: platform
module: eligibility
revision: 1
status: proposed
design_intent: confirmed
source_sha:
  services-platform: ad3f6a6582843008ed0f5a17b131878d15829af1
  react-console: baf6dae382d6f41dce976c7f848667ccc37e076f
decision: >-
  Edit only the draft, assign a new permanent number at publication, and restore
  old logic by publishing another release.
constrains:
  - DOM-PFM-ELG-001
  - STATE-PFM-ELG-002
  - WF-PFM-ELG-002
origin: >-
  Eligibility Engine architecture governance chapter 14 (versions, effective
  periods, rollback), approved by Andrew 2026-10-17 (PLAT-M11 "Decisions"); D-15
  (committed orders record the version used)
alternatives:
  - option: Modify released expressions
    why_not: Existing decisions and pins would change meaning.
  - option: Reactivate an old release number
    why_not: History would no longer describe releases in their publication order.
consequences:
  - Decisions and pins can identify the expression evaluated.
  - Disjoint effective periods support scheduled releases.
  - Publication compares the validated draft fingerprint before committing.
supersedes: []
evidence:
  - >-
    services-platform at ad3f6a6:
    docs/proposals/eligibility/17-decision-register.md;
    docs/milestones/PLAT-M11-eligibility-rules.md (Decisions)
  - >-
    services-platform at ad3f6a6: modules/eligibility/lifecycle.ts;
    docs/eligibility.md §2, §7.3
---
# Published versions are immutable and a rollback is a new version

## Context

A saved decision or pin must retain the meaning of the release it used.

## Decision

Edit only the draft, assign a new permanent number at publication, and restore old logic by publishing another release.

## Alternatives Considered

Modify released expressions: Existing decisions and pins would change meaning.

Reactivate an old release number: History would no longer describe releases in their publication order.

## Consequences

Decisions and pins can identify the expression evaluated. Disjoint effective periods support scheduled releases. Publication compares the validated draft fingerprint before committing.