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+Error codes and conditions returned by the app
+
+Expands on https://github.com/SK-EID/MID#326-error-conditions
+
+| Status Code | Error message | Reason |
+|-|-|-|
+| 400 | Required parameter {parameterName} missing | Mandatory parameter in request is missing or has incorrect format/value |
+| 401 | Failed to authorise | Authentication failed. Some request token might be expired. |
+| 403 | No permission | Relying Party has no permission to use requested capability |
+| 404 | Session does not exist | Session does not exist or has expired |
+| 405 | Method not allowed | _To be specified_ |
+| 408 | Timeout | The request timed out or communication with the ID-card took too long |
+| 418 | I'm a teapot | Failed to brew coffee with tea pot or app doesn't want to do this request |
+| 429 | Too many requests | The client sent too many requests in a given amount of time |
+| 444 | Cancelled | User cancelled authentication or exited the authentication app |
+| 445 | Card expired | Authentication failed due to expired ID-card |
+| 446 | Card locked | The user entered an incorrect PIN code too many times or tried using a locked card |
+| 447 | Card unreadable | The data on the ID-card’s NFC chip is unreadable or could not be scanned |
+| 448 | Card invalid | The ID-card returned invalid or mismatching information |
+| 500 | Internal error | Unknown error, app or phone broken. Restart recommended. |
+| 501 | Not implemented | The request is not supported by the authentication app (yet) |
+| 502 | Third party error | While using another service, like biometrical authentication, the respective app or service returned an invalid response |
+| 503 | Service unavailable | For when the app is not ready to handle the request. A specific cause should be returned as well. Use for temporary conditions. See [HTTP error 503](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/503) for more clarification. |
+| 504 | Third party timeout | While using another service, like biometrical authentication, the request to the other app or service timed out |