Not something we do often, and when we do, I tend to forget the “rules” of LegalNotice.  I’ve written this down, like some other posts, as a memory aide.

1993 was when it was added into Windows NT4.
2000ish Windows 2000 introduced Carriage Returns, by using the special character “,” as the delimiter.
2003ish Windows Server 2003 updated the Group Policy editor to accept a carriage return.

Stored in registry
Originally stored in HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon

  • LegalNoticeText
  • LegalNoticeCaption

Since the invention of Group Policy, the keys are stored under HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\policies\system

Limitations – LegalNoticeText

  • 512 characters maximum if you do not use Carriage Returns.
  • 512 characters per line if you do use Carriage Returns.
  • 2047 characters maximum.

A , will be wrapped with a “,” when written to the registry.
The display of the LegalNotice will timeout after 120 seconds.

Using AGPM?
You’ll be stuck with the Group Policy Editor unless you use Group Policy Preferences (GPP).
With GPP it becomes hardar (no GP Editor) and easier (Registry Wizard).
You could import the registry key from a workstation with the LegalNoticeText would want.