Last month, I got an interesting email from reader Ed that started:

Scott,

Please consider if this is viable, albeit challenging to book:

[UA]  DCA-BOS-YYZ-ORD-CLE-EWR // EWR-ZRH-IST, IST-IAD

The answer is yes it is possible, and what it means is that you can add a free circle trip onto roundtrip international United awards.

Hopefully readers of this blog are well acquainted with Free Oneways on United Awards, the most-read post I've written.

The central idea of free oneways is to take your free stopover at your home airport, then start a second trip from there on the same award.