LIH Prem

I would have to disagree with the advice not to purchase Comfort+ fares if that's what you are saying.

I booked a W fare (Delta ticket, delta metal, booked on delta.com; sfo-jfk) and got credit, I had the e-ticket receipt showing the underlying fare code, which was T. The fare code was TAVSA0CK, which if you deconstruct using the link I posted above is a Delta Comfort+ W fare.

At the time of purchase I could have simply purchased the regular economy T fare or paid the upsell for the W fare, which is what I did on delta.com. This fare has an underlying fare basis, which is T. I guess the Comfort+ W fare thing is sort of a modifier to the underlying T fare basis. Yet Delta considers it to be a separate Fare code, but in reality it isn't completely separate. (I can see that a real premium economy fare might be booked as a completely separate fare basis, but these are not like that.)

What is your full fare code that's shown on your e-ticket receipt from Delta?

Sure if somehow you were able to book a true W fare that starts with the letter W, then there is no other underlying fare for that, so sure, you probably want to avoid those especially if we can figure out how somebody could book something like that.

-David