What is a Flight Segment ?
 

The flight numbers on a route that I take regularly has been changed such that both legs are the same flight number.

Is this now 1 flight segment or 2 ?

From my practical experience, even though it is listed as a single flight (same number) it will count as 2 segments.

2 different flight numbers = 2 different segments

A segment is a non-stop point to point flight. You can have a multi-segment flight on the same aircraft with the same flight number. However, increasingly some US carriers have created multi-segment flights using the same flight number but including a change of aircraft. Gets very confusing. Also, on most segment bonuses, en route stops do not count as multiple segments. As confusing as why the terms "direct" and "nonstop" get used improperly, where the former may include several stops but no change of aircraft or flight number (i.e. multi-segment) and the latter exactly as it sounds, no stops from origin to destination.

ONE flight number, even if you had a million stops on this ONE flight number is equal to ONE and ONE segment only.

ONE!!!

Interestingly, when I searched on aircanada.com I found the following

"Fares shown do not include a September 11th Security Fee of up to a maximum of $10 US per one-way trip and a $3.10 US flight Segment Tax per flight segment. A flight segment is defined s a landing and take-off."

*SIGH*

When AC 142 used to be YVR YUL with a stopover in YYZ, you would only get one flight segment credited towards your status. That's one example of many I can give.

So sure, you can go by the definition of your above "bold", or you can go with mine, which affects your status. Of course, I have no idea what your initial intent was by asking this (whether it affected your status, or you just asked just for the hay of it).

The bolded extract that I quoted wasn't intended to contradict what you and others had said but just to point out the inconsistency in the definitions for different purposes.

I realize that the quote was from a section about fees and taxes not qualification for status.

Reason for asking this is that it will probably affect my status.

Understood.
Yeah, this is a mistake that most people make w.r.t. a status segment. Many think it's truly one takeoff and landing but it's simply a flight number. Common examples are with competition with NW... for example, UA frequently sets one flight number from a city to NW's MSP hub, but most often than not, there is "one stopover" at ORD. People think they're buying a direct flight from DTW to MSP and don't realize there's actually a stopover at ORD even though it's one flight number. YYZ MSP via ORD is a common UA one flight number as well. I can list a million other examples, but I think many here get the point.