The Travelocity guy avoided telling the whole story. They do provide relevant information, but if the government has the PNR with all the remarks in it, then it likely came from Travelocity or Sabre.
Travel agencies and 3rd-party web sites, such as Travelocity. put all this encoded stuff into the remarks section of the PNR, it's all that "H-" stuff. When the PNR is sent to the airline, NONE of the remarks are transmitted. The airline doesn't receive your IP address, for example. Seat numbers, phone and contact information are transmitted in Special Service Request (SSR) and/or Other Service Information (OSI) fields. One major exception is that Travelocity and AA share the same PNR when booking AA.
Now, the airlines have to send a whole bunch of data about you to the TSA to get clearance for you to board. Look up Secure Flight / APIS / AQQ and you can learn a little bit about it.