Setting History Logging for the System

You can choose whether or not to capture history with this setting.

The following system-wide setting is available to enable or disable history for all user sessions permanently: 

set system history  [on|off]

By default, history is on. When turned off, custom history records can be used on the operations where history is required, since it will be logged regardless of the global history setting. For more information, see MQL Command Reference: Set System.