Comment 7 for bug 1122183

After discussing this with APR, I think it might be too much work and too much risk of bad side-effects for too little value: in-view field invisibility is only advisory (e.g. the field is still visible in advanced search). If you want to put implied non-removable filters, you should use the action (potentially via a server action generating a window action with the right domain & context).

As for removing the field altogether, that strikes me as going against the idea of "invisible", in all openerp views "invisible" means the field is there and active, just not shown.