Copied information for ppt presented on TECH meeting

doc/vendor-ext/vendor-ext.md

 # Vendor Extensibility
+This is a mechanism for the APIs to re-use, extend their functionalities and data models and engage with third-party API frameworks. 
 
-DOC:Work in Progress
+Is defined on 3GPP TS 29.122 and 29.500 and is tightly connected with “supported-features” and feature negotiation
+
+## Supported Features in Publish API:
+![Publish Supported Features](../images/vendor-ext/publish_supported_features.png)
+
+## Types of vendor extensions
+
+**Data models**
+
+* Extend the information element with vendor specific fields
+### Fields have specific naming schemes:
+* Using the 6-digit IANA-assigned enterprise code:
+
+
+
+```
+  "vendorSpecific-010415": {
+        ...
+        }
+```
+
+* Using domain name:
+
+
+```
+"vendorSpecific-3gpp.org": {
+        ...
+        }
+```
+
+* Using URN:
+
+
+```
+"vendorSpecific-urn:3gpp:example": {
+        ...
+        }
+```
+
+## Discover Query Parameters
+
+* Provisioning of vendor-specific query parameters to support additional vendor-specific filtering criteria
+### A vendor-specific query parameter shall be encoded as follows:
+    
+* query parameter name: 
+
+
+```
+"vend-spec-<query parameter name>”
+```
+
+* query parameter value encoded as JSON object:
+    * "target" 
+    * "value"
+
+**Example:**
+```
+GET {apiRoot}/3gpp-monitoring-event/v1/{scsAsId}/subscriptions?vend-spec-max-reports={"target": "/maximumNumberOfReports", value: "6"} 
+```
 
 
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