Passenger with Reduced Mobility (PRM)
The definition of passengers with reduced mobility is understood to be:
any person whose mobility is reduced due to physical disability (locomotory or sensory) intellectual impairment, age, illness or any other cause of disability and who needs some degree of special accommodation or assistance over and above that provided to other passengers.
This requirement will become apparent from special requests made by the passengers and/or their family or by a medical authority or reported by airline personnel or industry-associated persons (travel agents, etc.).
The level of assistance required by the airport and/or the air carriers can vary depending on the different needs that people have when traveling by air. (IATA)