These vessels are normally employed for courier duty, and on occasion get disabled or shy of fuel.

She likes courier duty: it makes her feel she's achieving something.

"I shall require you to give up courier duty, of course," she said.

There were, he thought smugly, occasional advantages to courier duty after all.

Or, for that matter, one to visit on courier duties.

It was for a spot of simple courier duty.

I worried that they might have pressed you into courier duty somewhere.

Now we've been switched to diplomatic courier duty.

"Your courier duties wouldn't happen to take you anywhere near a facility where the Xindi are building a large-scale particle-beam weapon, would it?"

I may also require courier duties of you.