PNR & GDS Codes Guide

A plain-English reference for the status codes, class letters, and terminology that show up in raw Amadeus, Sabre, and Galileo output — written for travel consultants who read this stuff every day but occasionally need to double-check one.

Reading a segment line

Every airline segment in a PNR packs the same handful of facts into one dense line. The exact spacing varies by GDS, but the fields themselves are consistent. Here's a typical Amadeus/Sabre-style 24-hour segment:

 1  EK 185 K 20OCT 2 DXBBCN HK1  0815  1325  20OCT  E

EK 185 Carrier and flight number — Emirates flight 185
K Booking class letter (see the table below)
20OCT Departure date
2 Day of week, IATA numbering: 1=Monday … 7=Sunday, so 2 here means Tuesday
DXBBCN Origin and destination airport codes run together — Dubai to Barcelona
HK1 Status code (HK) plus passenger count (1)
0815 / 1325 Departure and arrival time, local to each airport
20OCT Arrival date — only shown separately when it differs from departure

A quick sanity check worth knowing: that day-of-week digit is computed by the airline's own system, which knows the real booking year — useful when a PNR text itself never states the year outright.

Status codes

The two letters right before the passenger count describe where that segment actually stands — confirmed, waitlisted, cancelled, and so on.

Code	Meaning
HK	Holding confirmed — the standard "all good" status
KK	Confirming — segment confirmed by the airline after being requested
KL	Waitlisted, confirmed — moved off the waitlist onto a confirmed seat
HL	Holding, waitlisted — still on the waitlist
HN	Holding, need — request sent, awaiting the airline's reply
NN	Need, requested — segment requested but not yet actioned
SS	Sold, confirmed — used mainly in original air-availability sell entries
UC	Unable to confirm — the request was declined
UN	Unable, does not operate — flight doesn't exist as requested
DK	Booked, schedule change — a Jetstar/low-cost-carrier variant of HK, often paired with schedule-change flags
XX / XK	Cancelled segment
WK	Waitlisted, confirmed by schedule change
RR	Reconfirmed

If a status code doesn't fall into "confirmed" territory (HK, KK, KL, DK), it's worth a second look before quoting a client — a waitlisted or unable-to-confirm segment isn't a booked seat yet.

Booking class letters

The single letter after the flight number is the fare/booking class — it tells you the cabin, but the exact letter-to-cabin mapping is set by each airline individually, so the same letter can mean different things on two different carriers. The table below is the common convention, not a universal rule.

Cabin	Typical letters
First	F, A, P
Business	J, C, D, I, Z
Premium Economy	W, E, R (varies widely by carrier)
Economy	Y, B, H, K, L, M, N, Q, S, T, V, X

A carrier like Emirates might use E for Premium Economy, while a carrier without that cabin at all — say Etihad or Qatar — simply doesn't issue that letter. When in doubt, cross-check against the specific airline's fare basis rather than assuming the general table above.

Connection vs. stopover

Both describe a gap between two segments at the same airport, and the distinction genuinely matters for how you present an itinerary to a client:

Connection

A short changeover — typically under 24 hours — where the passenger is just passing through on the way to their real destination. Worth noting the transit time, but not something the traveler experiences as "part of the trip."

Stopover

A longer break — conventionally 24 hours or more on international itineraries — where the passenger is meaningfully staying in that city before continuing. This is worth calling out clearly in a quote, since it changes what the traveler should expect (and sometimes what the fare rules allow).

One wrinkle worth knowing: on a genuine round trip or circle itinerary that loops back to where it started, the "gap" at the actual turnaround point isn't a connection or a stopover in the usual sense — it's simply the traveler's stay at their destination, however long or short. Worth keeping that distinction in mind when reading an itinerary rather than mechanically applying the 24-hour rule everywhere.

Common GDS terms

Term	Meaning
PNR	Passenger Name Record — the booking record itself, identified by a record locator (e.g. `SHJAD3`)
GDS	Global Distribution System — the booking platform (Amadeus, Sabre, Travelport/Galileo, Worldspan)
Fare basis	The code describing exactly which fare rules apply to a ticket, e.g. `KLXESAE1`
E-ticket	Electronic ticket number tied to the PNR, issued once the booking is ticketed
ARNK	"Arrival unknown" — a placeholder segment marking a gap in the itinerary the passenger arranges separately (e.g. an overland leg between two flights)
Open-jaw	A round trip where the return leg departs from (or arrives into) a different city than the outbound leg
Codeshare	A flight sold under one airline's code but operated by a different airline
SSR	Special Service Request — meal preferences, wheelchair assistance, passport details, and similar flags attached to a PNR
Involuntary schedule change	An airline-initiated change to a booked flight's time or routing after ticketing

Why durations look different across systems

A flight's departure and arrival times in a PNR are both local to their own airport — so the raw clock difference between them is rarely the actual flight time whenever the route crosses a timezone. A Casablanca–Dubai flight departing 14:40 and arriving 01:40 the next day looks like an 11-hour flight by the clock alone, but Casablanca sits at UTC+1 and Dubai at UTC+4 — a three-hour gap that has to be subtracted out to get the true block time, which comes to roughly 8 hours in that example. This is exactly the kind of arithmetic that's easy to get wrong by hand and easy to get right with the correct airport timezone data on hand.

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