diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a52d139..290e48e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -57,10 +57,10 @@ Think of these repositories as a pipeline: Contributors make changes in cve-data
 4. Install required Python packages:
    ```bash
    # If using uv
-   uv pip install requests check-jsonschema
+   uv pip install requests check-jsonschema cpe
 
    # If using pip
-   pip install requests check-jsonschema
+   pip install requests check-jsonschema cpe
    ```
 
 5. Fork and clone the cve-data-enrichment repository:
@@ -451,6 +451,57 @@ When creating CPEs:
 - Use asterisks (*) for fields that apply to all values
 - Ensure vendor and product names follow standardized formats
 
+### Scenario 6: Removing a match
+
+Sometimes a match needs to be removed from appearing in the results. There
+are many reasons this could happen: missing details for a very old
+vulnerability, the vulnerability might be marked as wontfix by the upstream
+project, or the original CPE is just incorrect.
+
+Using the example from Scenario 1
+
+```json
+{
+  "additionalMetadata": {
+    "cna": "github_m",
+    "cveId": "CVE-2025-23214",
+    "description": "Cosmos provides users the ability self-host a home server...",
+    "reason": "Added CPE configurations because not yet analyzed by NVD."
+  },
+  "adp": {
+    "affected": [
+      {
+        "collectionURL": "https://pkg.go.dev",
+        "cpes": [
+          "cpe:2.3:a:cosmos-cloud:cosmos_server:*:*:*:*:*:go:*:*"
+        ],
+        "packageName": "github.com/azukaar/cosmos-server",
+        "packageType": "go-module",
+        "product": "Cosmos-Server",
+        "repo": "https://github.com/azukaar/cosmos-server",
+        "vendor": "azukaar",
+        "versions": [
+          {
+            "lessThan": "0.17.7",
+            "status": "affected",
+            "version": "0",
+            "versionType": "custom"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+We will change the line
+`"status": "affected",`
+to be unaffected
+`"status": "unaffected",`
+
+We modify the status rather than removing the data so future script run
+won't mistakenly re-add the incorrect data.
+
 ## Best Practices
 
 1. **Documentation**: Always include clear commit messages explaining your changes. Examples: