diff --git a/rest-api-guidelines/functionality/message/error-reporting.md b/rest-api-guidelines/functionality/message/error-reporting.md
index 8ec785a..45eae79 100644
--- a/rest-api-guidelines/functionality/message/error-reporting.md
+++ b/rest-api-guidelines/functionality/message/error-reporting.md
@@ -124,8 +124,8 @@ A Problem Detail response **MUST NOT** contain a program stack trace or server l
 
 ## Working with Problem Detail
 
-An API description **SHOULD** list all the error codes with which the API responds. The error responses **SHOULD** describre the error object model schema. It is **RECOMMENDED** to include examples of a possible error response. The error description and/or error example **MAY** list all the types of errors returned for a given error code.
+An API description **CAN** list all the error codes with which the API responds. The error responses **SHOULD** describre the error object model schema. It is **RECOMMENDED** to include examples of a possible error response. The error description and/or error example **MAY** list all the types of errors returned for a given error code.
 
 ## External resources
 
-There are a whole plethora of libraries working with Problem Detail, for example, see [Zalando / Problem](https://github.com/zalando/problem) \(Java\).
\ No newline at end of file
+There are a whole plethora of libraries working with Problem Detail, for example, see [Zalando / Problem](https://github.com/zalando/problem) \(Java\).