Originally Posted by
sbm12
What is "composite availability?"
NWA.com is (seemingly mistakenly) showing that the seat is available which would explain why your tool shows it as there.
There is no mistake -- this is by [their] design. NWA.com shows 'composite' availability on the search screen (step 1), e.g.
CS- short-haul [+]
CS+ long-haul [=]
CS+ overall. Once a particular flight option is selected, it will display the booking class/cabin for each segment (in step 2).