Passengers carry documents on behalf of a company in return for a discounted, or free (though rarely), round trip.

携带公司证明文件的乘客可以换取折扣或者免费（虽然很罕见）的往返机票。

youdao

Recently, some passengers said, buy the same Airlines round-trip ticket, but did not catch the plane trip, return ticket can not use the normal.

近日，有旅客表示，购买同一航空公司的往返套票，但没赶上去程飞机，返程机票也无法正常使用了。

youdao

To buy a round-trip ticket, not to take the process, also cannot use the return.

购买往返飞机票，未乘去程，返程也无法使用。

youdao