Originally Posted by zrs70
Let's not debate whether my fare is unrestricted or not! That's not the issue. (This particular one IS, for the most part, unrestricted, though of course it is not a full F. Of note is that I paid a $70 add/ collect, and the new ticket is in DL F).
But I still have the questions, "Can an airline take our full value e-ticket and endorse it to any other carrier (that can read their e-ticket)? Must the airline be part of the same alliance? Can we take the ticket receipt and go to the other airline ourselves?
First off, this situation was nothing special. All the CO agent did was sell you a new ticket on DL flights with a DL price and apply your old Z ticket towards it, most likely without a penalty.
To answer your question, you will hardly ever see a fully endorseable ticket anymore since the "full fare" that is offered now as a result of DL's Simplifares is NON-endorseable. You would need to refund one and purchase another, even if both fares are unrestricted or even equal.
Airlines alliances have nothing to do with ticketing. There needs to be a ticketing agreement in place which is the case with almost all good carriers, that's all.
A ticket receipt will do nothing for you if the ticket is electronic. The original airline must give up control of the ticket first. Technically, they will not do this on a non-endorseable ticket, although of course YMMV.