Regulation (UE) n. 1177/2010 defines the rights of passengers with disabilities or reduced mobility (PMR) who are guaranteed rights of transport on the same conditions as those applying to all other passengers. If tickets are purchased on line, the PMR must check the ASSISTANCE box in the LIST OF PASSENGERS section. If the ticket is purchased through a call centre or travel agency the need for assistance must be communicated directly to the telephone operator or travel agent. Further information on the procedures to follow can be found at these link