Direct Actor-to-Actor Communication

That actors can communicate directly with each other without going through the system's internal objects — illustrated by a message arrow directly between two actor lifelines

Explanation

One of the additional features illustrated in the Transfer data sequence diagram is the direct communication between the actors in the system. A message arrow connects the Medical Receptionist actor's lifeline directly to the PRS actor's lifeline, showing that these two parties communicate directly (e.g., the receptionist logs in to the PRS) without routing through Mentcare's internal objects.