An old ticket-price tactic for airlines may make a surprise comeback, thanks to proposed legislation. Before a 2011 full-fare advertising rule forbade it, airlines displayed initial “base” ticket fares online without including the mandatory taxes and fees. The FAA Reauthorization Act of 2018, introduced recently, puts that rule in jeopardy. The bill funds the Federal Aviation Administration, but is also used for other purposes, such as revising aviation rules and consumer laws. If Congress passes the act in its current form, it will give airlines clearance to quote an initial, low ticket price and then add taxes and fees before you pay.