Specialisation of LINE for flexible service. <br/>NOTE1: As the service on a LINE may not all be flexible, flexibility itself is described at JOURNEY PATTERN level (meaning that a separate JOURNEY PATTERN is needed for each type of flexibility available for the line).<br/>NOTE2: Types of flexible services include: Virtual line services; Flexible service with a main route; Corridor services; Fixed stop area-wide flexible services; Free area-wide flexible services; Mixed combinations of flexible services of different types; Mixed combinations of flexible and regular services.<br/>