Trouble interpreting flight upgrade rules

[Moopere]

Hello knowledgeable SQ flyers. I seem to always struggle to interpret meaning with relation to SQ upgrades for some reason.

My latest effort is price/FF/SC comparison for an upcoming flight PER-KUL (one leg SQ and one MI).

On the relevant entry web page for upgrades this is stated:

"For redemption of upgrades from Economy to Premium Economy Class or Business Class, only tickets purchased in Y, B or E booking classes on flights operated by Singapore Airlines or SilkAir are eligible.
Please note that upgrade award tickets are offered on a one-class upgrade basis. Upgrades from Economy Class to Business Class are only applicable to flights without Premium Economy Class."

Which seems pretty clear. My understanding of the above is that on a flight like mine, where there is no PE, a Y to J upgrade requires that the Y booking class be Y:B or E. So far so good and not dissimilar to many other airlines.

However ... When you actually go to the booking engine, there are a myriad of much much cheaper options, 'Economy Super Saver', 'Economy Saver', 'Economy Flexi Saver' before you get to the 'Economy Flexi' where these Y, B and E classes are found. On each of the these cheaper options is an 'i' information button which, in the case of an 'Economy Super Saver' reads as this:

"Booking change **Fee Applies

• Refund/Cancellation
• Earn KrisFlyer miles on Singapore Airlines and SilkAir flights (10%)
• Upgrade with KrisFlyer miles on flights operated by Singapore Airlines and SilkAir. Codeshare flights are not eligible for upgrades (see the KrisFlyer terms and conditions) "

Which strongly suggests that upgrades -are- available ... whats going on here do you think? Am I lacking fundamental understanding or interpretation of something?

 

[Moopere]

Pondering my own question most of today ... one wonders if I've missed the most obvious reason for my perception of discrepancy.

Though normally the Super Saver Economy are N, Q, V, K classes, I guess its not necessarily always so. Theoretically, I suppose, any economy class could feed through the funnel of 'super saver' fares.

So, theres an important logical 'AND' statement (programming reference) in there which I chose to be blind to. Any economy fare AND being of class Y, B, E AND no PE available means a points upgrade to J might be available

Still open to being told the real deal if the above is wrong of course.