Originally Posted by
TomMM
Can the airlines block ticketing requests from a 3rd party?
Oh yes.
When I was a travel agent and we wrote tickets by hand, the airline plates (credit card sized er, cards with an embossed logo that validated the ticket) were highly prized.
BA sometimes used the threat of removing the plate when we booked a nested itinerary. The plate is now electronic, basically.
There's a selection of them here:
32 Vintage Airline Metal Ticket Validation Plates Collection 1 | #1924094412 (worthpoint.com)