If you book an airline ticket, odds are under the hood you're hitting an IBM TPF application (prolly PARS/IPARS). When I was involved in that world 20 some-odd

If you book an airline ticket, odds are under the hood you're hitting an IBM TPF application (prolly PARS/IPARS). When I was involved in that world 20 some-odd years ago the programmers would regularly show me files with 'last modified' in the 80's and 90's. These aren't things that someone casually modifies, and I would expect you'd find an awful lot of the same even now.