Originally Posted by
mnbp
As with many things DL, exactly which fares qualify for Amex cert use is opaque.
However, there is one thing certain - broken fares (more than one fare in each direction) won't work with the Amex cert.
I'mnot sure what you mean by opaque since it's in the terms, but you can certainly have different "fares" with the reserve card. You can have FC on one segment and coach on another.