Use this response when you propose new meeting times: registry value propose response typeUserHKCU\software\policies\microsoft\office\16.0\outlook\options\calendar

Policy ID
L_Usethisresponsewhenyouproposenewmeetingtimes
Scope
User Configuration
Supported on
At least Windows Server 2008 R2 or Windows 7
Source
Microsoft 365 Apps / Office Administrative Templates (version 5568.1000)
Category
Microsoft Outlook 2016 › Outlook Options › Preferences › Calendar Options

Registry

propose response type

REG_DWORDUser
Enabled value
Depends on the option value
Element
Use this response when you propose new meeting times
Options
ItemStored value
Tentative2
Accept3
Decline4
Apply with .reg · CMD · PowerShell
.reg
Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\options\calendar]

; Options (use only one)
; Tentative
"propose response type"=dword:00000002
; Accept
"propose response type"=dword:00000003
; Decline
"propose response type"=dword:00000004
CMD
:: Options (use only one)

:: Tentative
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\options\calendar" /v "propose response type" /t REG_DWORD /d 2 /f
:: Accept
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\options\calendar" /v "propose response type" /t REG_DWORD /d 3 /f
:: Decline
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\options\calendar" /v "propose response type" /t REG_DWORD /d 4 /f
PowerShell
# Common: create the key
New-Item -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\options\calendar' -Force | Out-Null

# Options (use only one)
# Tentative
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\options\calendar' -Name 'propose response type' -PropertyType DWord -Value 2 -Force | Out-Null
# Accept
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\options\calendar' -Name 'propose response type' -PropertyType DWord -Value 3 -Force | Out-Null
# Decline
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\options\calendar' -Name 'propose response type' -PropertyType DWord -Value 4 -Force | Out-Null