I remember reading some CRS manual in the 90s and one system had both FQTV and FQTS fields - the latter for status. I also remember the syntax was basically by passenger and segment.

Googling FQTV FQTS PNR turned up a few really old Flyertalk threads such as: Airlines that use FQTV & FQTS and https://www.flyertalk.com/forum/air-...ry-fields.html