Originally Posted by
UAAAPeter
so that one could hop on and off United (and others I guess) for long international flights like in the old days?
It seems to me that you are looking for the old IATA Y fare with flexible mileage based routing and unlimited stopovers. They still exist in tariff but no sane person will ever purchase them.
For example, JFK-SIN-JFK, fully flexible Y is $8072+, while you can get business class Z for $6342 and D for $7300.@:-)