Here is one of the 1925 Alaska Mercy Flight labels:

The story of these used to be that they were printed for a planned flight to Nome for delivery of emergency serum in the middle of the Alaskan winter. Supposedly, the weather wouldn't allow the flight, and dogsleds were used, instead.
Over the years, I've read a few stories debunking that story (no available planes, not enough time to print labels, no purpose, no contemporaneous record of charity sales of the labels).
I recall reading a new explanation a couple years ago, and now I can't find it.
Thoughts?
If you have any others to share, please do so.