MATLAB: Does the If Action block have vertical bars next to port names

action subsystemexecution contextsimulink

I inherited a model wherein every If Action block shows solid black bars along the edge of block outline, next to Inport and Outport names. It occurs even when I add a new Action block of my own.
Why?

Best Answer

It is an optional display to let you know if the execution context of the conditionally executed subsystem can propagate outside or not. This page covers this topic: Conditional Execution Behavior
See Displaying Execution Context Bars at the bottom of this page to turn it on and off.
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