Thanks for the reply Ditto! Yes you got that correctly, sorry for not providing exact routing, I thought it wasn't required, but certainly would have made it clearer. OK, I might have got the terminology wrong, I thought hidden-city means leaving the return flight a stop earlier (usually to save money). I know nothing will be cancelled, and I have no checked-in luggage, but my concern was more that airlines disapprove of not using all the booked segments.