diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/failure/MatrixError.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/failure/MatrixError.kt
index fb35940f34..bcff747b3b 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/failure/MatrixError.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/failure/MatrixError.kt
@@ -22,12 +22,16 @@ import com.squareup.moshi.JsonClass
 /**
  * This data class holds the error defined by the matrix specifications.
  * You shouldn't have to instantiate it.
+ * Ref: https://matrix.org/docs/spec/client_server/latest#api-standards
  */
 @JsonClass(generateAdapter = true)
 data class MatrixError(
+        /** unique string which can be used to handle an error message */
         @Json(name = "errcode") val code: String,
+        /** human-readable error message */
         @Json(name = "error") val message: String,
 
+        // For M_CONSENT_NOT_GIVEN
         @Json(name = "consent_uri") val consentUri: String? = null,
         // For M_RESOURCE_LIMIT_EXCEEDED
         @Json(name = "limit_type") val limitType: String? = null,
@@ -39,30 +43,90 @@ data class MatrixError(
 ) {
 
     companion object {
+        /** Forbidden access, e.g. joining a room without permission, failed login. */
         const val M_FORBIDDEN = "M_FORBIDDEN"
+        /** An unknown error has occurred. */
         const val M_UNKNOWN = "M_UNKNOWN"
+        /** The access token specified was not recognised. */
         const val M_UNKNOWN_TOKEN = "M_UNKNOWN_TOKEN"
+        /** No access token was specified for the request. */
         const val M_MISSING_TOKEN = "M_MISSING_TOKEN"
+        /** Request contained valid JSON, but it was malformed in some way, e.g. missing required keys, invalid values for keys. */
         const val M_BAD_JSON = "M_BAD_JSON"
+        /** Request did not contain valid JSON. */
         const val M_NOT_JSON = "M_NOT_JSON"
+        /** No resource was found for this request. */
         const val M_NOT_FOUND = "M_NOT_FOUND"
+        /** Too many requests have been sent in a short period of time. Wait a while then try again. */
         const val M_LIMIT_EXCEEDED = "M_LIMIT_EXCEEDED"
-        const val M_USER_IN_USE = "M_USER_IN_USE"
-        const val M_ROOM_IN_USE = "M_ROOM_IN_USE"
-        const val M_BAD_PAGINATION = "M_BAD_PAGINATION"
-        const val M_UNAUTHORIZED = "M_UNAUTHORIZED"
-        const val M_OLD_VERSION = "M_OLD_VERSION"
-        const val M_UNRECOGNIZED = "M_UNRECOGNIZED"
 
+        /* ==========================================================================================
+         * Other error codes the client might encounter are
+         * ========================================================================================== */
+
+        /** Encountered when trying to register a user ID which has been taken. */
+        const val M_USER_IN_USE = "M_USER_IN_USE"
+        /** Sent when the room alias given to the createRoom API is already in use. */
+        const val M_ROOM_IN_USE = "M_ROOM_IN_USE"
+        /** (Not documented yet) */
+        const val M_BAD_PAGINATION = "M_BAD_PAGINATION"
+        /** The request was not correctly authorized. Usually due to login failures. */
+        const val M_UNAUTHORIZED = "M_UNAUTHORIZED"
+        /** (Not documented yet) */
+        const val M_OLD_VERSION = "M_OLD_VERSION"
+        /** The server did not understand the request. */
+        const val M_UNRECOGNIZED = "M_UNRECOGNIZED"
+        /** (Not documented yet) */
         const val M_LOGIN_EMAIL_URL_NOT_YET = "M_LOGIN_EMAIL_URL_NOT_YET"
+        /** Authentication could not be performed on the third party identifier. */
         const val M_THREEPID_AUTH_FAILED = "M_THREEPID_AUTH_FAILED"
-        // Error code returned by the server when no account matches the given 3pid
+        /** Sent when a threepid given to an API cannot be used because no record matching the threepid was found. */
         const val M_THREEPID_NOT_FOUND = "M_THREEPID_NOT_FOUND"
+        /** Sent when a threepid given to an API cannot be used because the same threepid is already in use. */
         const val M_THREEPID_IN_USE = "M_THREEPID_IN_USE"
+        /** The client's request used a third party server, eg. identity server, that this server does not trust. */
         const val M_SERVER_NOT_TRUSTED = "M_SERVER_NOT_TRUSTED"
+        /** The request or entity was too large. */
         const val M_TOO_LARGE = "M_TOO_LARGE"
+        /** (Not documented yet) */
         const val M_CONSENT_NOT_GIVEN = "M_CONSENT_NOT_GIVEN"
+        /** The request cannot be completed because the homeserver has reached a resource limit imposed on it. For example,
+         *  a homeserver held in a shared hosting environment may reach a resource limit if it starts using too much memory
+         *  or disk space. The error MUST have an admin_contact field to provide the user receiving the error a place to reach
+         *  out to. Typically, this error will appear on routes which attempt to modify state (eg: sending messages, account
+         *  data, etc) and not routes which only read state (eg: /sync, get account data, etc). */
         const val M_RESOURCE_LIMIT_EXCEEDED = "M_RESOURCE_LIMIT_EXCEEDED"
+        /** The user ID associated with the request has been deactivated. Typically for endpoints that prove authentication, such as /login. */
+        const val M_USER_DEACTIVATED = "M_USER_DEACTIVATED"
+        /** Encountered when trying to register a user ID which is not valid. */
+        const val M_INVALID_USERNAME = "M_INVALID_USERNAME"
+        /** Sent when the initial state given to the createRoom API is invalid. */
+        const val M_INVALID_ROOM_STATE = "M_INVALID_ROOM_STATE"
+        /** The server does not permit this third party identifier. This may happen if the server only permits,
+         *  for example, email addresses from a particular domain. */
+        const val M_THREEPID_DENIED = "M_THREEPID_DENIED"
+        /** The client's request to create a room used a room version that the server does not support. */
+        const val M_UNSUPPORTED_ROOM_VERSION = "M_UNSUPPORTED_ROOM_VERSION"
+        /** The client attempted to join a room that has a version the server does not support.
+         *  Inspect the room_version property of the error response for the room's version. */
+        const val M_INCOMPATIBLE_ROOM_VERSION = "M_INCOMPATIBLE_ROOM_VERSION"
+        /** The state change requested cannot be performed, such as attempting to unban a user who is not banned. */
+        const val M_BAD_STATE = "M_BAD_STATE"
+        /** The room or resource does not permit guests to access it. */
+        const val M_GUEST_ACCESS_FORBIDDEN = "M_GUEST_ACCESS_FORBIDDEN"
+        /** A Captcha is required to complete the request. */
+        const val M_CAPTCHA_NEEDED = "M_CAPTCHA_NEEDED"
+        /** The Captcha provided did not match what was expected. */
+        const val M_CAPTCHA_INVALID = "M_CAPTCHA_INVALID"
+        /** A required parameter was missing from the request. */
+        const val M_MISSING_PARAM = "M_MISSING_PARAM"
+        /** A parameter that was specified has the wrong value. For example, the server expected an integer and instead received a string. */
+        const val M_INVALID_PARAM = "M_INVALID_PARAM"
+        /** The resource being requested is reserved by an application service, or the application service making the request has not created the resource. */
+        const val M_EXCLUSIVE = "M_EXCLUSIVE"
+        /** The user is unable to reject an invite to join the server notices room. See the Server Notices module for more information. */
+        const val M_CANNOT_LEAVE_SERVER_NOTICE_ROOM = "M_CANNOT_LEAVE_SERVER_NOTICE_ROOM"
+        /** (Not documented yet) */
         const val M_WRONG_ROOM_KEYS_VERSION = "M_WRONG_ROOM_KEYS_VERSION"
 
         // Possible value for "limit_type"