This rulemaking action would enhance protections for air travelers and to improve the air travel environment, including clarification  and codification of the Department's interpretation of the statutory definition of ticket agent.” This action would also require airlines and ticket agents to disclose at all points of sale the fees for certain basic ancillary services associated with the air transportation consumers are buying or considering buying. This action would also enhance additional airline passenger protections, such as: expanding the pool of reporting” carriers; requiring enhanced reporting by mainline carriers for their domestic code-share partner operations; requiring large travel agents to adopt minimum customer service standards; codifying the statutory requirements that carriers and ticket agents disclose any code-share arrangements on their websites; and prohibiting unfair and deceptive practices such as undisclosed biasing and post-purchase price increases. This action would require ticket agents to disclose the carriers whose tickets they sell in order to avoid having consumers mistakenly believe they are searching all possible flight options for a particular city-pair market when in fact there may be other options available. Additionally, this action would correct drafting errors and make minor changes to the Department's second Enhancing Airline Passenger Protections rule to conform to guidance issued by the Department's Office of Aviation Enforcement and Proceedings (Enforcement Office) regarding its interpretation of the rule.