As reported by RealityCheck over at usaviation.com:

<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Today, pricing revised the use it or lose policy on the higher non ref fares.. like the 10 day or 21 day adv no sat stay ones Ive heard about here.. from memory they can run from 600 to 1800 or so RT(like a be101mns or be211mn).. but were classified in the same lump as the real cheap fares for changes by trvl time.. now you can "FLOAT" these as before up to a year with 100 chg fee as it was b4... </font>

It's pretty consistent with the "drive them to higher fares" theory. I don't see anything on the web site yet. Maybe it's in the fare rules? (Can't find any examples at the moment...)

So let's say this is the case. Am I to understand then that my $112 RT non-refundable, use it or lose it fare is the bottom of the ladder....and the next step up is a $600 fare? Pay five times more to lose that restriction? Boy these guys are just flailing.

Lets suppose that $112 fare requires 14 day advance and a Saturday night minimum stayover. The fares mentioned above are usally 10 day advance with no Saturday minimum stay , usually 1-2 nite min stay. So with less advance purchase its high but stilll better than a roundtrip B8US at possibly $900-$3200 which used to be the case before all this happened. This is just another response to all the concern over use it or lose it. The fares end with -NZ. I believe PHL-CMH is one market.

How am I supposed to know which fares are use-it-or-lose-it and which are not when I book anywhere but with Corp Travel or US directly via phone? None of the web sites I have checked have a way to clearly select/indicate this.

And how is the general public supposed to figure it out if this group of "experts" can't figure it out?

This seems pretty consistant with NW Biz Flex fares. When NW went to "use it or lose it," they excluded those fares from the new rules. Looks like US is creating its own "Biz Flex" type of fare.

There seems to be some discussion that maybe they will leave open a cancellation if you do it weeks ahead of time so that you do not have to have new flights in hand. I guess a new nuance about cancel 2 hours before, you are out the door; cancel 2 weeks ahead, you are safe instead; will be added to the rules. This will mean that soon the ticket rules will be longer the Code of Federal Regulations.

BTW, I have 27 volumes of the federal environmental regulations.