Interrupting
The Interrupting attribute shows that the selected shape interrupts the current process flow. When enabling the interrupting option, it will create non-broken lines around the selected shape.
Interrupting applies only to Event Sub-Process, a defined Start Event and a defined catching Intermediate Event…

This will create a visual queue on around the shape for a defined Start Event.

This will create a visual queue inside the shape for a Event Sub-Process.
