Message field restrictions

Last updated October 21st, 2026

As part of our commitment to strengthening product security, starting with Knox Guard 26.10, certain special characters aren’t supported in messages and can’t be entered.

Blocked characters include: < > | ~ ` ^ \ =

This restriction impacts all device actions, policies, and endpoints in the Knox Guard API with a Message input field. Configurations set prior to the 26.10 release continue to function without issue. However, creating, updating, or re-applying any policy with blocked characters returns an error.

In addition, blocked characters may be removed or modified from CSV file exports. As such, you may notice that the values in the exported file differ from the original input in the Knox Guard console. This applies even to legacy activity log entries created before this restriction was introduced. The original values stored in your policies aren’t modified.

List of impacted features

The following tables lists the features impacted by this restriction.

Knox Guard console

The device actions impacted by the blocked characters restrictions are as follows:

Device action	Impacted field
Complete device management	Message
Lock and unlock devices	Message
Manage firmware update control	Message
Outgoing call control	Message
Send notifications	Notification
Send relock timestamp and turn the relock reminder ON and OFF	Message
Start and stop blinking reminder	Message
Update app access control	Warning notification
Update enrollment management	Customize message
Update lock message	Message
Update or disable offline lock policy	Warning notification Offline device lock message

The policies impacted by the blocked characters restrictions are as follows:

Policy	Impacted field
App access control	Warning notification
Blinking reminder	Message
Enrollment management	Customize message
Firmware update control	Message
Lock screen	Message
Notifications	Notification
Offline device lock	Offline device lock message Warning notification
Pay-as-you-go lock screen	Message
Relock reminder	Message
SIM control policy	Message Locked device message

Knox Guard API

The endpoints impacted by the blocked characters restrictions are as follows:

Endpoint	Async endpoint	Impacted field
Set blinking reminders	Set blinking reminders	`message`
Complete device management	Complete device management	`message`
Send relock timestamp or update the lock message	—	`actions[].message`
Lock a device	Lock devices	`message`
Send message to a device	Send message to devices	`message`
—	Send custom messages to devices	`deviceMessageList[].message`
Unlock a device	Unlock devices	`message`
Update the lock message	Update the lock message	`message`
Update the offline lock policy	Update the offline lock policy	`warningMessage` `lockMessage`
Update the enrollment notice policy	Update the enrollment notice policy	`enrollmentNotice.message` `enrollmentNotice.simCardNotice.message`
Set relock reminders	Set relock reminders	`message`
Lock offline device	—	`lockMessage` `warningMessage`
Set SIM control policy	—	`lockMessage` `restrictionMessage.message` `imsiRestrictionInfo.lockMessage` `restrictionInfoList[].lockMessage` `restrictionInfoList[].restrictionMessage.message`
Update the app access control policy	Update the app access control policy	`appAccessNotification.warningMessage`
Update outgoing call controls	Update outgoing call controls	`message`

Message field restrictions

List of impacted features

Knox Guard console

Knox Guard API

On this page