diff --git a/CHANGELOG.md b/CHANGELOG.md
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+++ b/CHANGELOG.md
@@ -0,0 +1,33 @@
+# Changelog
+
+All notable changes to this guide should be documented in this file.
+
+## [Unreleased]
+### Added
+- Operational implementation sections in README:
+  - Implementation Quickstart (30/60/90)
+  - Evaluation Harness (Reference Implementation)
+  - Agentic AI Attack Trees + Controls Mapping
+  - AI Harm Severity and Triage Model
+  - Secure SDLC Integration Artifacts
+  - Defensive Architecture Patterns
+  - Multilingual & Cultural Safety Playbook
+  - Data Governance for Red Teaming
+  - Metrics That Matter (and Anti-Metrics)
+  - Purple Team Operations
+  - Common Implementation Pitfalls
+  - Case Study Quality Bar
+  - Model & System Cards for Security Posture
+  - Source Hygiene & Update Governance
+  - Practitioner Appendices
+- New templates in `templates/`:
+  - threat-modeling-workshop.md
+  - ai-security-pr-checklist.md
+  - rules-of-engagement-template.md
+  - vulnerability-report-template.md
+  - test-case-library-starter.md
+  - stakeholder-readout-outline.md
+  - model-system-security-card.md
+  - case-study-template.md
+- `resources-validation.md` to track external source freshness.
+- `.github/workflows/ai-redteam-regression.yml` baseline CI workflow.
diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1887,6 +1887,181 @@ To reduce "one-off" testing, integrate red-team controls into delivery workflows
 - New jailbreak family with repeat success
 - Evidence of cross-tenant leakage or autonomous unsafe tool use
 
+## 🛡️ Defensive Architecture Patterns
+
+Translate red-team findings into architecture decisions using a layered control model:
+
+### Reference Pipeline
+```
+User Input
+  -> Input normalization/sanitization
+  -> Policy-as-code pre-checks
+  -> Prompt orchestration with role boundaries
+  -> Retrieval/tool authorization gates
+  -> Model inference
+  -> Output policy and leakage filters
+  -> Human-in-the-loop (for high-risk actions)
+  -> Logging, telemetry, and audit trail
+```
+
+### Core Patterns
+1. **Secure Prompt Orchestration**
+   - Separate system, developer, and user instructions
+   - Prevent untrusted content from altering control prompts
+
+2. **Tool Permissioning and Isolation**
+   - Grant least-privilege tokens per tool and per action
+   - Use approval workflows for sensitive actions (payments, credential resets)
+
+3. **Policy-as-Code Enforcement**
+   - Implement deterministic checks before tool execution
+   - Version policies and test them in CI alongside prompts
+
+4. **Output Guardrails**
+   - Add layered filters (policy, PII, compliance)
+   - Require citations for high-stakes domains where applicable
+
+---
+
+## 🌍 Multilingual & Cultural Safety Playbook
+
+### Test Set Design
+- Cover top business languages + low-resource languages in your user base
+- Include region-specific harmful-content categories and local legal constraints
+- Add culturally sensitive edge cases (slang, euphemisms, coded hate terms)
+
+### Required Test Patterns
+- **Translation-loop bypass**: blocked request translated across 2+ languages
+- **Mixed-language prompt injection**: instructions split across languages/scripts
+- **Code-switching attacks**: alternating dialect/locale variants per turn
+- **Contextual harm variance**: same request across regions with different norms
+
+### Reporting Requirements
+- Record language, locale, and script for every failure
+- Track ASR by language family to identify uneven safety coverage
+- Prioritize mitigation where user impact and language penetration are highest
+
+---
+
+## 🗂️ Data Governance for Red Teaming
+
+### Data Classes in Scope
+- Prompts and conversational logs
+- Retrieved documents and memory artifacts
+- Model outputs (including blocked/flagged outputs)
+- Metadata containing user identifiers or tenant references
+
+### Handling Rules (Baseline)
+- Minimize data collection to testing necessity
+- Pseudonymize/anonymize PII before long-term storage
+- Encrypt findings repositories and restrict access by role
+- Define retention windows per data class (e.g., 30/90/365 days)
+- Run legal/compliance review for regulated environments
+
+### Governance Checkpoints
+- Pre-engagement data handling approval
+- Mid-engagement privacy compliance review
+- Post-engagement purge and evidence retention sign-off
+
+---
+
+## 📊 Metrics That Matter (and Anti-Metrics)
+
+### Outcome Metrics (Use)
+- **ASR by risk category** (not only aggregate ASR)
+- **Exploit recurrence rate** after fixes
+- **Median time-to-fix** by severity
+- **Residual risk trend** by quarter
+- **Control coverage** across high-risk abuse paths
+
+### Anti-Metrics (Avoid)
+- Raw number of tests executed without risk weighting
+- Total vulnerabilities found as a standalone success metric
+- Single-point benchmark scores without trend context
+- “Pass rate” without confidence interval/sample-size disclosure
+
+---
+
+## 🟣 Purple Team Operations
+
+### Operating Cadence
+1. Red team identifies exploit chain and reproduction steps
+2. Detection engineering maps telemetry and creates detections
+3. Incident response drafts/updates response runbook
+4. Product and platform teams ship mitigations
+5. Purple-team replay validates detection + containment effectiveness
+
+### Required Outputs
+- Detection rule specifications linked to finding IDs
+- Incident runbooks for top critical/high abuse paths
+- Post-exercise retro: what failed, what improved, what's next
+
+---
+
+## ⚠️ Common Implementation Pitfalls
+
+| Pitfall | Why It Fails | What Good Looks Like |
+|--------|---------------|----------------------|
+| Keyword-only blocking | Easy to bypass via encoding/obfuscation | Semantic + policy layered controls |
+| Over-trusting agent tools | Enables privilege escalation | Strong authz checks per tool action |
+| One-time red team exercise | Misses drift and regressions | Recurring automated + manual cadence |
+| Tracking only aggregate ASR | Hides high-risk hotspots | Risk-tiered metrics and trends |
+| No regression suite | Reintroduces old vulnerabilities | Versioned attack library in CI |
+
+---
+
+## 🧾 Case Study Quality Bar
+
+Use a normalized template for all future case studies:
+- System context and business criticality
+- Attack chain with reproducible steps
+- Root cause and control failure points
+- Severity and estimated remediation effort
+- Evidence quality tag (**Evidence-backed** or **Expert guidance**)
+- Confidence level (High/Medium/Low)
+- Lessons learned and prevention actions
+
+Template available: `templates/case-study-template.md`
+
+---
+
+## 🪪 Model & System Cards for Security Posture
+
+Document security posture using a structured card for every production AI system:
+- Intended use and prohibited use
+- Attack surface summary
+- Tested risk categories and latest validation date
+- Open risks and compensating controls
+- Incident escalation owners and contacts
+
+Template available: `templates/model-system-security-card.md`
+
+---
+
+## 🔄 Source Hygiene & Update Governance
+
+### Governance Practices
+- Maintain a versioned changelog for the guide (`CHANGELOG.md`)
+- Track external references with "last validated" timestamps
+- Mark major claims as **Evidence-backed** or **Expert guidance**
+- Run a quarterly review for stale links/tools/framework updates
+
+Reference index available: `resources-validation.md`
+
+---
+
+## 📎 Practitioner Appendices
+
+Starter artifacts in `templates/`:
+- `threat-modeling-workshop.md`
+- `ai-security-pr-checklist.md`
+- `rules-of-engagement-template.md`
+- `vulnerability-report-template.md`
+- `test-case-library-starter.md`
+- `stakeholder-readout-outline.md`
+- `model-system-security-card.md`
+- `case-study-template.md`
+
 
 ## 📋 Regulatory Compliance
 
diff --git a/resources-validation.md b/resources-validation.md
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+++ b/resources-validation.md
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+# External Resources Validation Index
+
+Track major external references to keep this guide current.
+
+| Resource | Type | Last Validated | Evidence Tag | Notes |
+|----------|------|----------------|--------------|-------|
+| NIST AI RMF | Framework | 2026-02-19 | Evidence-backed | Core governance reference |
+| OWASP GenAI Guide | Framework | 2026-02-19 | Evidence-backed | Practical LLM testing guidance |
+| MITRE ATLAS | Framework | 2026-02-19 | Evidence-backed | Tactics and techniques mapping |
+| CSA Agentic AI Guide | Framework | 2026-02-19 | Evidence-backed | Agentic-specific threat coverage |
+
+## Update Process
+1. Validate links and publication status quarterly.
+2. Update `Last Validated` dates.
+3. Mark major additions as Evidence-backed or Expert guidance.
diff --git a/templates/case-study-template.md b/templates/case-study-template.md
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+# AI Red Team Case Study Template
+
+## Context
+- System description:
+- Business criticality:
+- Deployment context:
+
+## Attack Chain
+1.
+2.
+3.
+
+## Finding Details
+- Vulnerability class:
+- Root cause:
+- Controls bypassed:
+- Severity:
+
+## Impact and Cost
+- User/business impact:
+- Estimated remediation effort:
+
+## Evidence and Confidence
+- Evidence quality: Evidence-backed / Expert guidance
+- Confidence level: High / Medium / Low
+- Sources:
+
+## Remediation and Validation
+- Immediate mitigation:
+- Long-term control improvements:
+- Regression test coverage added:
+
+## Lessons Learned
+- What changed in process/architecture:
diff --git a/templates/model-system-security-card.md b/templates/model-system-security-card.md
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+# Model/System Security Card
+
+## System Identity
+- Name:
+- Owner:
+- Environment:
+- Last updated:
+
+## Intended and Prohibited Use
+- Intended use:
+- Prohibited use:
+
+## Architecture and Attack Surface
+- Interfaces (API/UI/agents/tools):
+- Trust boundaries:
+- High-value assets:
+
+## Controls
+- Preventive controls:
+- Detective controls:
+- Corrective controls:
+
+## Test Coverage
+- Categories tested:
+- Latest validation date:
+- Known coverage gaps:
+
+## Open Risks
+- Risk description:
+- Severity:
+- Compensating controls:
+- Target remediation date:
+
+## Incident Readiness
+- On-call owner:
+- Escalation path:
+- Runbook link:
diff --git a/templates/rules-of-engagement-template.md b/templates/rules-of-engagement-template.md
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+# Red Team Rules of Engagement (Template)
+
+## Scope
+- In scope:
+- Out of scope:
+
+## Authorized Techniques
+- Allowed:
+- Prohibited:
+
+## Safety Guardrails
+- No production data export
+- Rate limits and resource ceilings
+- Mandatory stop conditions
+
+## Escalation and Notification
+- Critical finding notification SLA:
+- Security contact:
+- Legal/compliance contact:
+
+## Data Handling
+- Data classes used:
+- Retention period:
+- Deletion and evidence procedures:
+
+## Sign-off
+- Red Team Lead:
+- System Owner:
+- Security Lead:
+- Legal/Compliance:
diff --git a/templates/stakeholder-readout-outline.md b/templates/stakeholder-readout-outline.md
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+# Stakeholder Readout Outline (AI Red Teaming)
+
+## 1. Executive Summary
+- Top risks discovered
+- Current risk posture trend
+- Decision requests for leadership
+
+## 2. Engagement Scope
+- Systems and versions tested
+- Timeframe and constraints
+- Threat assumptions
+
+## 3. Key Findings
+- Critical/high findings summary
+- Notable exploit chains
+- Residual risk after mitigation
+
+## 4. Metrics Dashboard
+- ASR by category
+- Recurrence rate
+- Time-to-fix trend
+- Control coverage
+
+## 5. Action Plan
+- Immediate (0-30 days)
+- Near-term (31-90 days)
+- Strategic (90+ days)
+
+## 6. Appendix
+- Methodology
+- Evidence and confidence levels
+- Open questions
diff --git a/templates/test-case-library-starter.md b/templates/test-case-library-starter.md
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+# Test Case Library Starter Pack
+
+## Naming Convention
+`<category>-<technique>-<id>`
+
+## Required Metadata Per Test
+- Test ID
+- Category (prompt injection/jailbreak/data leakage/etc.)
+- Risk tier (critical/high/medium/low)
+- Target component (model, retrieval, tool, orchestrator)
+- Language/locale
+- Expected policy outcome
+- Last validated date
+
+## Starter Categories
+1. Prompt injection (direct/indirect)
+2. Jailbreak (single-turn/multi-turn)
+3. Data leakage (PII/training-data exposure)
+4. Tool misuse (agentic)
+5. Memory poisoning (agentic)
+6. Cross-tenant isolation checks
+
+## Regression Policy
+- Critical/high tests run on every PR
+- Full suite run on release branches
+- Failed tests require linked mitigation issue
diff --git a/templates/vulnerability-report-template.md b/templates/vulnerability-report-template.md
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+# AI Vulnerability Report (Template)
+
+## Finding Metadata
+- Finding ID:
+- Date discovered:
+- Reporter:
+- Affected system/version:
+
+## Severity and Risk
+- Severity (Critical/High/Medium/Low):
+- Exploitability:
+- User impact:
+- Autonomy factor:
+- Blast radius:
+- Recoverability:
+
+## Reproduction
+- Preconditions:
+- Step-by-step reproduction:
+- Proof of concept:
+
+## Impact
+- Security/privacy/safety impact:
+- Business impact:
+
+## Root Cause
+- Control(s) bypassed:
+- Why mitigation failed:
+
+## Remediation
+- Immediate containment:
+- Long-term fix:
+- Owner:
+- Target date:
+
+## Validation
+- Regression test case ID:
+- Validation status/date: