What's a shared code carrier?

Here's a recent email: "I was checking airfares on-line and kept noticing the term “shared code carrier”. What’s that a small plane?"

It has nothing to do with airplane size or engine type. It is an airline term used to a list a smaller sized carrier as that of a larger airline. For example when you fly on Allegiant Air out of Huntington Tri-State you are flying on Allegiant proper. But when you fly Delta you’ll start your journey on Comair-the shared code/dual designated carrier. You flight may seem like Delta roundtrip but there may be other partner airlines flying under the Delta logo.

Got travel questions? Email thetravelprofessor@gmail.com.