; (B) economic and operational factors which result in oversales; (C) whether, and if so how, the incidence of oversales varies depending on markets; (D) potential consequences on the limiting of oversales; and (E) best practices on how oversale policies can be communicated to passengers at airline check-in desks and airport gates. (3) Report Not later than 1 year after the date of enactment of this Act, the Comptroller General shall submit to the appropriate committees of Congress a report on the review under paragraph (2). (g) Gate notice of policies The Secretary may provide guidance on how these policies should be communicated at covered air carrier check-in desks and airport gates. 426. Report on availability of lavatories on commercial aircraft Not later than 180 days after the date of enactment of this Act, the Comptroller General of the United States shall submit to the appropriate committees of Congress a report assessing— (1) the availability of functional lavatories on commercial aircraft (2) the extent to which flights take off without functional lavatories; (3) the ability of passengers with disabilities to access lavatories on commercial aircraft; (4) the extent of complaints to the Department of Transportation and air carriers related to lavatories and efforts they have taken to address complaints