Just a further heads up. This ticket class ONLY affects UK-GVA and GVA-UK tickets. If you have a connection on wards from GVA (both long and short haul) then this ticket is not an option and you will still have a free baggage allowance of 23KG for the whole journey. For example LHR-GVA-ATH or LHR-GVA-JFK will still have a free bag allowance as standard!
If you book two separate tickets then be sure that you are booking a fare which includes a bag on any GVA-UK/UK-GVA leg or you will need to pay for the baggage on that leg.