diff --git a/cmd/syncthing/cli/errors.go b/cmd/syncthing/cli/errors.go
index 8847ce962..52ace7128 100644
--- a/cmd/syncthing/cli/errors.go
+++ b/cmd/syncthing/cli/errors.go
@@ -27,7 +27,7 @@ var errorsCommand = cli.Command{
 		{
 			Name:      "push",
 			Usage:     "Push an error to active clients",
-			ArgsUsage: "[error message]",
+			ArgsUsage: "ERROR-MESSAGE",
 			Action:    expects(1, errorsPush),
 		},
 		{
diff --git a/cmd/syncthing/cli/operations.go b/cmd/syncthing/cli/operations.go
index bef49cc92..d84e67e15 100644
--- a/cmd/syncthing/cli/operations.go
+++ b/cmd/syncthing/cli/operations.go
@@ -39,13 +39,13 @@ var operationCommand = cli.Command{
 		{
 			Name:      "folder-override",
 			Usage:     "Override changes on folder (remote for sendonly, local for receiveonly). WARNING: Destructive - deletes/changes your data.",
-			ArgsUsage: "[folder id]",
+			ArgsUsage: "FOLDER-ID",
 			Action:    expects(1, foldersOverride),
 		},
 		{
 			Name:      "default-ignores",
 			Usage:     "Set the default ignores (config) from a file",
-			ArgsUsage: "path",
+			ArgsUsage: "PATH",
 			Action:    expects(1, setDefaultIgnores),
 		},
 	},
diff --git a/gui/default/syncthing/core/eventService.js b/gui/default/syncthing/core/eventService.js
index 0d873dfcc..7e528d5a3 100644
--- a/gui/default/syncthing/core/eventService.js
+++ b/gui/default/syncthing/core/eventService.js
@@ -65,18 +65,25 @@ angular.module('syncthing.core')
             DEVICE_PAUSED: 'DevicePaused',   // Emitted when a device has been paused
             DEVICE_RESUMED: 'DeviceResumed',   // Emitted when a device has been resumed
             DOWNLOAD_PROGRESS: 'DownloadProgress',   // Emitted during file downloads for each folder for each file
+            FAILURE: 'Failure',   // Specific errors sent to the usage reporting server for diagnosis
             FOLDER_COMPLETION: 'FolderCompletion',   //Emitted when the local or remote contents for a folder changes
             FOLDER_REJECTED: 'FolderRejected',   // DEPRECATED: Emitted when a device sends index information for a folder we do not have, or have but do not share with the device in question
             PENDING_FOLDERS_CHANGED: 'PendingFoldersChanged',   // Emitted when pending folders were added / updated (offered by some device, but not shared to them) or removed (folder ignored or added or no longer offered from the remote device)
             FOLDER_SUMMARY: 'FolderSummary',   // Emitted when folder contents have changed locally
             ITEM_FINISHED: 'ItemFinished',   // Generated when Syncthing ends synchronizing a file to a newer version
             ITEM_STARTED: 'ItemStarted',   // Generated when Syncthing begins synchronizing a file to a newer version
+            LISTEN_ADDRESSES_CHANGED: 'ListenAddressesChanged',   // Listen address resolution has changed.
+            LOCAL_CHANGE_DETECTED: 'LocalChangeDetected',   // Generated upon scan whenever the local disk has discovered an updated file from the previous scan.
             LOCAL_INDEX_UPDATED: 'LocalIndexUpdated',   // Generated when the local index information has changed, due to synchronizing one or more items from the cluster or discovering local changes during a scan
+            LOGIN_ATTEMPT: 'LoginAttempt',   // Emitted on every login attempt when authentication is enabled for the GUI.
+            REMOTE_CHANGE_DETECTED: 'RemoteChangeDetected',   // Generated upon scan whenever a file is locally updated due to a remote change.
+            REMOTE_DOWNLOAD_PROGRESS: 'RemoteDownloadProgress',   // DownloadProgress message received from a connected remote device.
             REMOTE_INDEX_UPDATED: 'RemoteIndexUpdated',   // Generated each time new index information is received from a device
             STARTING: 'Starting',   // Emitted exactly once, when Syncthing starts, before parsing configuration etc
             STARTUP_COMPLETED: 'StartupCompleted',   // Emitted exactly once, when initialization is complete and Syncthing is ready to start exchanging data with other devices
             STATE_CHANGED: 'StateChanged',   // Emitted when a folder changes state
             FOLDER_ERRORS: 'FolderErrors',   // Emitted when a folder has errors preventing a full sync
+            FOLDER_WATCH_STATE_CHANGED: 'FolderWatchStateChanged',   // Watcher routine encountered a new error, or a previous error disappeared after retrying.
             FOLDER_SCAN_PROGRESS: 'FolderScanProgress',   // Emitted every ScanProgressIntervalS seconds, indicating how far into the scan it is at.
             FOLDER_PAUSED: 'FolderPaused',   // Emitted when a folder is paused
             FOLDER_RESUMED: 'FolderResumed',   // Emitted when a folder is resumed
diff --git a/lib/api/api.go b/lib/api/api.go
index 35d7e1a13..5d121734b 100644
--- a/lib/api/api.go
+++ b/lib/api/api.go
@@ -59,6 +59,8 @@ import (
 )
 
 const (
+	// Default mask excludes these very noisy event types to avoid filling the pipe.
+	// FIXME: ItemStarted and ItemFinished should be excluded for the same reason.
 	DefaultEventMask      = events.AllEvents &^ events.LocalChangeDetected &^ events.RemoteChangeDetected
 	DiskEventMask         = events.LocalChangeDetected | events.RemoteChangeDetected
 	EventSubBufferSize    = 1000
diff --git a/lib/model/folder.go b/lib/model/folder.go
index a9b15e0de..30fddd2d9 100644
--- a/lib/model/folder.go
+++ b/lib/model/folder.go
@@ -1038,7 +1038,7 @@ func (f *folder) setWatchError(err error, nextTryIn time.Duration) {
 	f.watchErr = err
 	f.watchMut.Unlock()
 	if err != prevErr {
-		data := map[string]interface{}{
+		data := map[string]string{
 			"folder": f.ID,
 		}
 		if prevErr != nil {