Maybe you were referring to this: 2. Boarding Priorities - If a flight is Oversold, no one may be denied boarding against his/her will until UA or other carrie

Maybe you were referring to this: 2. Boarding Priorities - If a flight is Oversold, no one may be denied boarding against his/her will until UA or other carrier personnel first ask for volunteers who will give up their reservations WILLINGLY in exchange for compensation as determined by UA. If there are not enough volunteers, other Passengers may be denied boarding involuntarily in accordance with UA’s boarding priority: + Passengers who are Qualified Individuals with Disabilities, unaccompanied minors under the age of 18 years, or minors between the ages of 5 to 15 years who use the unaccompanied minor service, will be the last to be involuntarily denied boarding if it is determined by UA that such denial would constitute a hardship. + The priority of all other confirmed passengers may be determined based on a passenger’s fare class, itinerary, status of frequent flyer program membership, and the time in which the passenger presents him/herself for check-in without advanced seat assignment. Some relevant points: >> no one may be denied boarding against his/her will until UA or other carrier personnel first ask for volunteers who will give up their reservations WILLINGLY in exchange for compensation as determined by UA >> If there are not enough volunteers, other Passengers may be denied boarding involuntarily in accordance with UA’s boarding priority Note that after the phrase UA's boarding priority, it explicitly stated that: the time in which the passenger presents him/herself for check-in without advanced seat assignment. This is very clear that their IDB clause is solely focused on a person not yet physically inside the plane, with a seat allocated to him/her. Again, contracts and clauses are always open to different (mis)interpretations and the bias goes down to which entity one would want it favorable to. Update: Capitalized the word Willingly as it is implied in this contract.