Which type of order indicates ongoing instructions without affecting train movement?

The answer is General Notice (GN), which serves to provide ongoing information or instructions that do not directly impact the movement of the train. General Notices are used to communicate updates that may be important for the crew's awareness but do not involve immediate operational changes that would alter how the train operates at that moment.

Options like General Order, Bulletin Order, and Operations Notice pertain to directives that can involve adjustments to train operations, including speed restrictions or alterations in route. General Orders typically outline specific changes that need to be executed, while Bulletin Orders can convey crucial safety information or alerts that could affect train movement directly or require immediate attention. Operations Notices also relate to operational procedures but may carry implications that could lead to changes in train handling or performance. Thus, General Notice is focused strictly on ongoing information that maintains the status quo regarding train movement.