Originally Posted by
kyotoben
Yes, exactly. When you buy a ticket from a company that codeshares with another airline which "operates" the flight, then your ticket will not have the original flight number ( e.g. AF123 for Air France...) but will appear as a flight number with the company you bought the ticket from (e.g. JL3456). In the example of Air France, as long as your ticket would start with JL... (which happens if you buy it via the JAL website) it would be considered by JAL as one of their own group flights, even though it is technically not...
I think it would be good to more explicitly clarify that not all partner flights sold on the JAL website are codeshares.
For example, from Paris to Tokyo, you can fly on Qatar with a layover in Doha. The first segment may be sold as QR040 and the second segment as JL7994 with both flights being operated by Qatar. Even though the entire itinerary was booked through the JAL website, only the second flight is a codeshare that counts as a JAL flight while the first flight will not.