"denied boarding" means a refusal to carry passengers on a flight, although they have presented themselves for boarding u
nder the conditions laid down in Article 3(2), except where there are reasonable grounds to deny them boarding, such as reasons of health, safety or security, or inadequate travel documentation; (k) "volunteer" means a person who has presented himself for boarding u
nder the conditions laid down in Article 3(2) and responds po
sitively to the air carrier's ...[+++]call for passengers prepared to surrender their reservation in exchange for benefits;
"refus d'embarquement", le refus de transporter des passagers sur un vol, bien qu'ils se soient présentés à l'embarquement dans les conditions fixées à l'article 3, paragraphe 2, sauf s'il est raisonnablement justifié de refuser l'embarquement, notamment pour des raisons de santé, de sûreté ou de sécurité, ou de documents de voyages inadéquats