Update docs (22023)

Signed-off-by: Nester.zhou <ester.zhou@huawei.com>

en/application-dev/reference/errorcodes/Readme-EN.md

@@ -55,6 +55,7 @@
   - [Network Connection Management Error Codes](errorcode-net-connection.md)
   - [Ethernet Connection Error Codes](errorcode-net-ethernet.md)
   - [Network Sharing Error Codes](errorcode-net-sharing.md)
+  - [Policy Management Error Codes](errorcode-net-policy.md)
   - [mDNS Error Codes](errorcode-net-mdns.md)
   - [Traffic Management Error Codes](errorcode-net-statistics.md)
 - Connectivity

en/application-dev/reference/errorcodes/errorcode-universal.md

@@ -44,7 +44,7 @@ BusinessError 401: Parameter error. The type of "${parameterName}" must be ${val
 
 **Description**
 
-This error code is reported when a parameter error occurs.
+This error code is reported when a parameter error occurs. Regardless of whether the API is synchronous or asynchronous, this type of error is generally thrown in synchronous mode.
 
 **Possible Causes**