dublindispatch, what's WABS? Google has offered several possibilities, but none particularly relevant to the subject.....
WAB (never heard it spelt with an S before!) is bmi's weight and balance system used to produce loadsheets etc... it stands for Weight And Balance, clever huh?
Its a LH System, and actually works rather well - I certainly miss it now I have nothing to do with bmi! It pulls figures across from the pretty, but actually fairly useless (in my experience) 'Frontcheck' check in system.
As dublindispatch mentioned, using the correct version (ie seating/catering config) of a particular aircraft can be a bit of a nightmare, especially with their being quite a few versions in service, as well as a whole myriad of versions previously used.
If the cabin is likely to still be 'segregated' in Frontcheck/WAB (ie C & Y 'cabins'), does this mean that flexible economy pax are restricted to the front few rows of the cabin and can't sit elsewhere?