From the "search this forum" box, type in KVS and you will see threads on KVS - one has directions on how to request access. You then do a download and install on your PC. It is a tool which allows you to see the number of seats in each fare bucket.

There are two versions: one free - more limited only one reservation system and a second one - with more accesss to more systems - requires a donation be mailed to the creator of the tool (he is in Canada).

First you email and requested access to the free version - then KVS mails you back a free license code.
If you mail a contribution (he says average contribution has been $30) you get an upgraded license code - which gives full access to about six reservations systems - one of which shows the number of "R" class on CO which is the upgrade availability code. (Although the license is only for 6 months).

Not really access to reservation systems - but when you type in to/from airline (in some cases) and time - you get the full range of fare buckets.