The PNR is a bit of a nightmare, but you have to keep in mind that the PNR itself and the interfaces to manipulate and transfer it have been backwards compatibl

The PNR is a bit of a nightmare, but you have to keep in mind that the PNR itself and the interfaces to manipulate and transfer it have been backwards compatible since the mid-70s. The PNR won't go away soon, however what is important is to move it away from the end user (whether traveller or agent) and relegate it to a low-level data format. Using PNR+last name as a form of "secure" identification is crazy for example.