Selection of identifiers

A method comprising:

• receiving identifier information for one or more identifiers displayable at a vehicle mountable display device;
• storing the identifier information for at least one of the one or more identifiers;
• determining a location parameter relating to the vehicle mountable display device;
• selecting an identifier for display at the vehicle mountable display device based, at least in part, on the stored identifier information for the at least one of the one or more identifiers matching the location parameter relating to the vehicle mountable display device;
• and
• receiving a communication from the vehicle mountable display device indicating movement of the vehicle mountable display device, the communication comprising a request for reauthorisation of the vehicle mountable display device for display of an identifier.

A non-transitory computer-readable storage medium encoded with instructions which are executable by a processor to:

• obtain identifier parameters for one or more identifiers displayable at a vehicle mountable display device;
• select an identifier for display at the vehicle mountable display device based, at least in part, on the obtained identifier parameters for at least one of the one or more identifiers matching a location parameter relating to the vehicle mountable display device;
• and
• obtain a communication received from the vehicle mountable display device indicating movement of the vehicle mountable display device, the communication comprising a request for reauthorisation of the vehicle mountable display device for display of an identifier.