diff --git a/Comments:BIP-0171.md b/Comments:BIP-0171.md
index efdf17d..c55c42f 100644
--- a/Comments:BIP-0171.md
+++ b/Comments:BIP-0171.md
@@ -8,14 +8,55 @@ I just released CERISE ([website](http://www.cerise.tech/) & [github](https://gi
 
 Stéphane Traumat ( @straumat )
 ***
+# Error management proposal (straumat)
+
+These are the different http status : 
+* `200` : Everything worked as expected.
+* `400` : The request was unacceptable, often due to missing a required parameter.
+* `401` : No valid authorization was provided.
+* `402` : The parameters were valid but the request failed.
+* `404` : The requested resource doesn't exist.
+* `500` : Something went wrong on the server.
+
+In case of error, we always return this object : 
+``` 
+{
+  "type": "invalid_request_error",
+  "message": "Invalid request to enumerating supported currency-pair",
+  "errors": [
+    {
+      "code": "currency_code_invalid",
+      "message": "Invalid currency code : AAA"
+    },
+    {
+      "code": "currency_code_invalid",
+      "message": "Invalid currency code : BBB"
+    },
+    {
+      "code": "locale_invalid",
+      "message": "Invalid locale : UN_UN"
+    }
+  ]
+}
+```
+
+`Type` : The type of error returned. One of api_connection_error, api_error, authentication_error, invalid_request_error or rate_limit_error.
+
+`message` : A human-readable message providing more details about the error.
+
+and then you have all the errors with, for each error found : 
+
+`code` : Error code like currency_code_invalid.
+
+`message` : A human-readable message providing more details about the error.
+
+***
+
+
 **Change to make in the BIP ?**
 “a GET request to a common URI with parameters encoded in application/x-www-form-urlencoded format” 
 May I ask you why parameters should be encoded this way ? From what I have seen in other projects, they also allow json for get method.
 
-There is no description on how to return error messages ?
-For the moment, for any error, I return this message structure : {"message":"Currency-pair should be no longer than 255 characters","errors":["‘AAAAA.AAAA’ should be no longer than 255 characters", "‘BBBBB.BBBB’ should be no longer than 255 characters"]}
-The message field contains the error message and you can use errors to detail every errors found.
-
 In the samples you provided, all returned fields are not set. For example, signature is never set. Of course it’s not a problem but I think it would be a good idea to have at least a result with all fields set so i could implement all the unit test cases.
 I have the same comment for “archive” and “signature” fiedls in Currency-pair information.
 I have the same comment for “minrate” and “maxrate” parameters in Current exchange rate and nonce in result.
@@ -25,4 +66,4 @@ I have the same comment for “minrate” and “maxrate” parameters in Curren
 **Things I don’t understand.**
 I don’t understand what means “XBTUSD-ver4” ? I don’t see what it means.
 “Currency-pair information \ symbol : Any positive or negative symbols must be included in this prefix/suffix” I don’t understand this rule. Can you explain it more please ?
-“grouping” : can you provide more informations about how it works ? I don’t understand if it’s only 3 fields or if you can have more ?
\ No newline at end of file
+“grouping” : can you provide more informations about how it works ? I don’t understand if it’s only 3 fields or if you can have more ?