The mission itinerary was a schedule of stops and objectives for a starship's ongoing mission.
In 2365, William T. Riker was surprised when Captain Jean-Luc Picard informed the crew that the USS Enterprise-D would be making a stop at Starbase Montgomery, as he didn't recall seeing it on the mission itinerary. Picard explained that aside from giving the crew a layover, it also allowed him to fulfill some personnel transfer directives. (TNG: "The Icarus Factor")