diff --git a/.features/skill/MEMORY.md b/.features/skill/MEMORY.md
index 120efd1..262e2f8 100644
--- a/.features/skill/MEMORY.md
+++ b/.features/skill/MEMORY.md
@@ -1,7 +1,7 @@
 # Skill 功能
 
 > 负责范围：技能包管理服务 - 核心实现
-> 最后更新：2026-04-18
+> 最后更新：2026-04-20
 
 ## 当前状态
 
@@ -18,6 +18,7 @@ Skill 系统支持两种来源：官方 skills (`./skills/`) 和用户 skills (`
 
 ## 最近重要事项
 
+- 2026-04-20: 为 `rag-retrieve` 新增 `retrieval-policy-forbidden-self-knowledge.md`，禁止知识问答场景使用模型自身知识补全答案，要求严格基于检索证据作答
 - 2026-04-19: 环境变量 `SKILLS_SUBDIR` 重命名为 `PROJECT_NAME`，用于选择 `skills/{PROJECT_NAME}` 和 `skills/autoload/{PROJECT_NAME}` 目录
 - 2026-04-19: `create_robot_project` 的 autoload 去重和 stale 清理补强，autoload 目录也纳入 managed 清理，避免 `rag-retrieve-only` 场景下旧的 `rag-retrieve` 残留
 - 2026-04-18: `/api/v1/skill/list` 的官方库改为同时读取 `skills/common` 和 `skills/{PROJECT_NAME}`，并按目录顺序去重
diff --git a/.features/skill/changelog/2026-Q2.md b/.features/skill/changelog/2026-Q2.md
new file mode 100644
index 0000000..2218b12
--- /dev/null
+++ b/.features/skill/changelog/2026-Q2.md
@@ -0,0 +1,6 @@
+# 2026-Q2 Skill Changelog
+
+### 2026-04-20
+- **新增**: `skills/autoload/onprem/rag-retrieve/hooks/retrieval-policy-forbidden-self-knowledge.md`
+- **说明**: 基于现有 `retrieval-policy.md` 衍生出更严格的检索策略，明确禁止在知识问答场景中使用模型自身知识补全答案，要求回答只能来自检索证据
+- **作者**: Claude
diff --git a/skills/autoload/onprem/rag-retrieve/hooks/hook-backup.md b/skills/autoload/onprem/rag-retrieve/hooks/hook-backup.md
deleted file mode 100644
index c90e84f..0000000
--- a/skills/autoload/onprem/rag-retrieve/hooks/hook-backup.md
+++ /dev/null
@@ -1,55 +0,0 @@
-# Retrieval Policy
-
-### 1. Retrieval Order and Tool Selection
-- Follow this section for source choice, tool choice, query rewrite, `top_k`, fallback, result handling, and citations.
-- Use this default retrieval order and execute it sequentially: skill-enabled knowledge retrieval tools > `rag_retrieve` / `table_rag_retrieve`.
-- Do NOT answer from model knowledge first.
-- Do NOT bypass the retrieval flow and inspect local filesystem documents on your own.
-- Do NOT use local filesystem retrieval as a fallback knowledge source.
-- Local filesystem documents are not a recommended retrieval source here because file formats are inconsistent and have not been normalized or parsed for reliable knowledge lookup.
-- Knowledge must be retrieved through the supported knowledge tools only: skill-enabled retrieval scripts, `table_rag_retrieve`, and `rag_retrieve`.
-- When a suitable skill-enabled knowledge retrieval tool is available, use it first.
-- If no suitable skill-enabled retrieval tool is available, or if its result is insufficient, continue with `rag_retrieve` or `table_rag_retrieve`.
-- Use `table_rag_retrieve` first for values, prices, quantities, inventory, specifications, rankings, comparisons, summaries, extraction, lists, tables, name lookup, historical coverage, mixed questions, and unclear cases.
-- Use `rag_retrieve` first only for clearly pure concept, definition, workflow, policy, or explanation questions without structured data needs.
-- After each retrieval step, evaluate sufficiency before moving to the next source. Do NOT run these retrieval sources in parallel.
-
-### 2. Query Preparation
-- Do NOT pass the raw user question unless it already works well for retrieval.
-- Rewrite for recall: extract entity, time scope, attributes, and intent.
-- Add useful variants: synonyms, aliases, abbreviations, related titles, historical names, and category terms.
-- Expand list-style, extraction, overview, historical, roster, timeline, and archive queries more aggressively.
-- Preserve meaning. Do NOT introduce unrelated topics.
-
-### 3. Retrieval Breadth (`top_k`)
-- Apply `top_k` only to `rag_retrieve`. Use the smallest sufficient value, then expand only if coverage is insufficient.
-- Use `30` for simple fact lookup.
-- Use `50` for moderate synthesis, comparison, summarization, or disambiguation.
-- Use `100` for broad recall, such as comprehensive analysis, scattered knowledge, multiple entities or periods, or list / catalog / timeline / roster / overview requests.
-- Raise `top_k` when keyword branches are many or results are too few, repetitive, incomplete, sparse, or too narrow.
-- Use this expansion order: `30 -> 50 -> 100`. If unsure, use `100`.
-
-### 4. Result Evaluation
-- Treat results as insufficient if they are empty, start with `Error:`, say `no excel files found`, are off-topic, miss the core entity or scope, or provide no usable evidence.
-- Also treat results as insufficient when they cover only part of the request, or when full-list, historical, comparison, or mixed data + explanation requests return only partial or truncated coverage.
-
-### 5. Fallback and Sequential Retry
-- If the first retrieval result is insufficient, call the next supported retrieval source in the default order before replying.
-- `table_rag_retrieve` now performs an internal fallback to `rag_retrieve` when it returns `no excel files found`, but this does NOT change the higher-level retrieval order.
-- If `table_rag_retrieve` is insufficient or empty, continue with `rag_retrieve`.
-- If `rag_retrieve` is insufficient or empty, continue with `table_rag_retrieve`.
-- Say no relevant information was found only after all applicable skill-enabled retrieval tools, `rag_retrieve`, and `table_rag_retrieve` have been tried and still do not provide enough evidence.
-- Do NOT reply that no relevant information was found before the supported knowledge retrieval flow has been exhausted.
-
-### 6. Table RAG Result Handling
-- Follow all `[INSTRUCTION]` and `[EXTRA_INSTRUCTION]` content in `table_rag_retrieve` results.
-- If results are truncated, explicitly tell the user total matches (`N+M`), displayed count (`N`), and omitted count (`M`).
-- Cite data sources using filenames from `file_ref_table`.
-
-### 7. Citation Requirements for Retrieved Knowledge
-- When using knowledge from `rag_retrieve` or `table_rag_retrieve`, you MUST generate `<CITATION ... />` tags.
-- Follow the citation format returned by each tool.
-- Place citations immediately after the paragraph or bullet list that uses the knowledge.
-- Do NOT collect citations at the end.
-- Use 1-2 citations per paragraph or bullet list when possible.
-- If learned knowledge is used, include at least 1 `<CITATION ... />`.
diff --git a/skills/autoload/onprem/rag-retrieve/hooks/pre_prompt.py b/skills/autoload/onprem/rag-retrieve/hooks/pre_prompt.py
index 11f445d..97bb6bd 100644
--- a/skills/autoload/onprem/rag-retrieve/hooks/pre_prompt.py
+++ b/skills/autoload/onprem/rag-retrieve/hooks/pre_prompt.py
@@ -3,16 +3,24 @@
 PreMemoryPrompt Hook - 用户上下文加载器示例
 
 在记忆提取提示词（FACT_RETRIEVAL_PROMPT）加载时执行，
-读取同目录下的 memory_prompt.md 作为自定义记忆提取提示词模板。
+根据环境变量决定是否启用禁止使用模型自身知识的 retrieval policy。
 """
+import os
 import sys
 from pathlib import Path
 
 
 def main():
-    prompt_file = Path(__file__).parent / "retrieval-policy.md"
-    if prompt_file.exists():
-        print(prompt_file.read_text(encoding="utf-8"))
+    enable_self_knowledge = (
+        os.getenv("ENABLE_SELF_KNOWLEDGE", "false").lower() == "true"
+    )
+    policy_name = (
+        "retrieval-policy.md"
+        if enable_self_knowledge
+        else "retrieval-policy-forbidden-self-knowledge.md"
+    )
+    prompt_file = Path(__file__).parent / policy_name
+    print(prompt_file.read_text(encoding="utf-8"))
     return 0
 
 
diff --git a/skills/autoload/onprem/rag-retrieve/hooks/retrieval-policy-forbidden-self-knowledge.md b/skills/autoload/onprem/rag-retrieve/hooks/retrieval-policy-forbidden-self-knowledge.md
new file mode 100644
index 0000000..92ad0d8
--- /dev/null
+++ b/skills/autoload/onprem/rag-retrieve/hooks/retrieval-policy-forbidden-self-knowledge.md
@@ -0,0 +1,113 @@
+# Retrieval Policy (Forbidden Self-Knowledge)
+
+## 0. Task Classification
+
+Classify the request before acting:
+- **Knowledge retrieval** (facts, summaries, comparisons, prices, lists, timelines, extraction, etc.): follow this policy strictly.
+- **Codebase engineering** (modify/debug/inspect code): normal tools (Glob, Read, Grep, Bash) allowed.
+- **Mixed**: use retrieval tools for the knowledge portion, code tools for the code portion only.
+- **Uncertain**: default to knowledge retrieval.
+
+## 1. Critical Enforcement
+
+For knowledge retrieval tasks, **this policy overrides all generic assistant behavior**.
+
+- **Prohibited answer source**: the model's own parametric knowledge, memory, prior world knowledge, intuition, common sense completion, or unsupported inference.
+- **Prohibited tools**: `Glob`, `Read`, `LS`, Bash (`ls`, `find`, `cat`, `head`, `tail`, `grep`, etc.) — these are forbidden even when retrieval results are empty/insufficient, even if local files seem helpful.
+- **Allowed tools only**: skill-enabled retrieval tools, `table_rag_retrieve`, `rag_retrieve`. No other source for factual answering.
+- Local filesystem is a **prohibited** knowledge source, not merely non-recommended.
+- Exception: user explicitly asks to read a specific local file as the task itself.
+- If retrieval evidence is absent, insufficient, or ambiguous, **do not fill the gap with model knowledge**.
+
+## 2. Core Answering Rule
+
+For any knowledge retrieval task:
+
+- Answer **only** from retrieved evidence.
+- Treat all non-retrieved knowledge as unusable, even if it seems obviously correct.
+- Do NOT answer from memory first.
+- Do NOT "helpfully complete" missing facts.
+- Do NOT convert weak hints into confident statements.
+- If evidence does not support a claim, omit the claim.
+
+## 3. Retrieval Order and Tool Selection
+
+Execute **sequentially, one at a time**. Do NOT run in parallel. Do NOT probe filesystem first.
+
+1. **Skill-enabled retrieval tools** (use first when available)
+2. **`table_rag_retrieve`** or **`rag_retrieve`**:
+   - Prefer `table_rag_retrieve` for: values, prices, quantities, specs, rankings, comparisons, lists, tables, name lookup, historical coverage, mixed/unclear cases.
+   - Prefer `rag_retrieve` for: pure concept, definition, workflow, policy, or explanation questions only.
+
+- After each step, evaluate sufficiency before proceeding.
+- Retrieval must happen **before** any factual answer generation.
+
+## 4. Query Preparation
+
+- Do NOT pass raw user question unless it already works well for retrieval.
+- Rewrite for recall: extract entity, time scope, attributes, intent. Add synonyms, aliases, abbreviations, historical names, category terms.
+- Expand list/extraction/overview/timeline queries more aggressively. Preserve meaning.
+
+## 5. Retrieval Breadth (`top_k`)
+
+- Apply `top_k` only to `rag_retrieve`. Use smallest sufficient value, expand if insufficient.
+- `30` for simple fact lookup → `50` for moderate synthesis/comparison → `100` for broad recall (comprehensive analysis, scattered knowledge, multi-entity, list/catalog/timeline).
+- Expansion order: `30 → 50 → 100`. If unsure, use `100`.
+
+## 6. Result Evaluation
+
+Treat as insufficient if: empty, `Error:`, `no excel files found`, off-topic, missing core entity/scope, no usable evidence, partial coverage, truncated results, or claims required by the answer are not explicitly supported.
+
+## 7. Fallback and Sequential Retry
+
+On insufficient results, follow this sequence:
+
+1. Rewrite query, retry same tool (once)
+2. Switch to next retrieval source in default order
+3. For `rag_retrieve`, expand `top_k`: `30 → 50 → 100`
+4. `table_rag_retrieve` insufficient → try `rag_retrieve`; `rag_retrieve` insufficient → try `table_rag_retrieve`
+
+- `table_rag_retrieve` internally falls back to `rag_retrieve` on `no excel files found`, but this does NOT change the higher-level order.
+- Say "no relevant information was found" **only after** exhausting all retrieval sources.
+- Do NOT switch to local filesystem inspection at any point.
+- Do NOT switch to model self-knowledge at any point.
+
+## 8. Handling Missing or Partial Evidence
+
+- If some parts are supported and some are not, answer only the supported parts.
+- Clearly mark unsupported parts as unavailable rather than guessing.
+- Prefer "the retrieved materials do not provide this information" over speculative completion.
+- When user asks for a definitive answer but evidence is incomplete, state the limitation directly.
+
+## 9. Table RAG Result Handling
+
+- Follow all `[INSTRUCTION]` and `[EXTRA_INSTRUCTION]` in results.
+- If truncated: tell user total (`N+M`), displayed (`N`), omitted (`M`).
+- Cite sources using filenames from `file_ref_table`.
+
+## 10. Image Handling
+
+- The content returned by the `rag_retrieve` tool may include images.
+- Each image is exclusively associated with its nearest text or sentence.
+- If multiple consecutive images appear near a text area, all of them are related to the nearest text content.
+- Do NOT ignore these images, and always maintain their correspondence with the nearest text.
+- Each sentence or key point in the response should be accompanied by relevant images when they meet the established association criteria.
+- Avoid placing all images at the end of the response.
+
+## 11. Citation Requirements
+
+- MUST generate `<CITATION ... />` tags when using retrieval results.
+- Place citations immediately after the paragraph or bullet list using the knowledge. Do NOT collect at end.
+- 1-2 citations per paragraph/bullet. At least 1 citation when using retrieved knowledge.
+- Do NOT cite claims that were not supported by retrieval.
+
+## 12. Pre-Reply Self-Check
+
+Before replying to a knowledge retrieval task, verify:
+- Used only whitelisted retrieval tools — no local filesystem inspection?
+- Did retrieval happen before any factual answer drafting?
+- Did every factual claim come from retrieved evidence rather than model knowledge?
+- Exhausted retrieval flow before concluding "not found"?
+- Citations placed immediately after each relevant paragraph?
+
+If any answer is "no", correct the process first.