Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
Verified with Microsoft Edge 152.0.4191.53 — updated on July 10, 2026
Supported on: Microsoft Edge version 127-132, Windows 7 or later
Path in the GPO console
Computer Configuration\Administrative Templates\Microsoft Edge User Configuration\Administrative Templates\Microsoft Edge Description
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 132. The :--foo syntax for the CSS custom state feature is being changed to :state(foo) in Microsoft Edge to comply with changes that are made in Firefox and Safari. This policy allows the deprecated syntax to be used until Stable 132. This deprecation breaks some Microsoft Edge-only websites that use the deprecated :--foo syntax. If you enable this policy, the deprecated syntax is enabled. If you disable or don't configure this policy, the deprecated syntax is disabled.
Registry
HKLM
Software\Policies\Microsoft\Edge HKCU
Software\Policies\Microsoft\Edge Value name: CSSCustomStateDeprecatedSyntaxEnabled
Enabled: CSSCustomStateDeprecatedSyntaxEnabled = 1
Disabled: CSSCustomStateDeprecatedSyntaxEnabled = 0
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
Applying both scopes creates an ambiguous configuration (computer takes precedence over user). Only do this intentionally.
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: Microsoft Edge version 127-132, Windows 7 or later
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge]
"CSSCustomStateDeprecatedSyntaxEnabled"=dword:00000001More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'CSSCustomStateDeprecatedSyntaxEnabled' -Value 1 -Type DWordIntune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'CSSCustomStateDeprecatedSyntaxEnabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'CSSCustomStateDeprecatedSyntaxEnabled' -Value 1 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'CSSCustomStateDeprecatedSyntaxEnabled' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Controls whether the deprecated :--foo syntax for CSS custom state is enabled (obsolete)
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 127-132, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'CSSCustomStateDeprecatedSyntaxEnabled' -Value 1 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.