Allow only approved domains to use the TDC ActiveX control
This setting controls whether websites in the Restricted Sites security zone can run the Internet Explorer Tabular Data Control (TDC).
since 0.9.8.11
Purpose
Show registry keys (2)
HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4\120cHKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4\120c
This setting controls whether websites in the Restricted Sites security zone can run the Internet Explorer Tabular Data Control (TDC). TDC is an ActiveX control that enables webpages to load data from text files and bind it to HTML elements such as tables and form controls.
Despite the wording of the display name, Microsoft defines the policy states as follows: when the policy is enabled, the TDC ActiveX control cannot run on any website in this zone. When the policy is disabled, the control can run on all websites in the zone.
Notes
Security
Blocking the TDC control prevents websites classified as restricted from instantiating this legacy ActiveX component. This reduces the active-content attack surface available to those sites.
Allowing the control enables websites in the Restricted Sites zone to use its tabular-data loading and processing capabilities. It does not authorize arbitrary ActiveX controls and does not override other security policies, permissions, or zone restrictions.
Possible side effects
Legacy web applications that depend on TDC for data display or data binding might not work fully when the control is blocked in this zone. In particular, affected pages might fail to display tabular content or related form data as intended.
Notes
The Zones\4 key represents the Restricted Sites zone. The setting is available in both computer and user policy scope, so the value can exist under either HKLM or HKCU.
This policy applies to legacy Internet Explorer technology. Microsoft Edge does not support ActiveX during normal page rendering. Microsoft Edge Internet Explorer mode does, however, support ActiveX controls and Internet Explorer policies that affect security-zone settings.
Microsoft documentation
Microsoft Learn: What is Internet Explorer mode?