What is a reply message's notation?

A reply message in the context of modeling notation is represented by a dashed line with an open arrowhead. This representation is used to indicate that it is a message sent in response to another message, creating a clear visual distinction between different types of interactions in a sequence diagram. The dashed line signifies that the message is a reply, which typically follows a preceding solid line message that initiates the communication.

Using this notation allows modelers to effectively communicate the flow of messages and the interactions between different components within a system. It enhances the clarity of how messages are exchanged, highlighting synchronous and asynchronous communications, and making it easier for stakeholders to understand the sequence and nature of these interactions in a modeled scenario.