Constraint applied

Says how many lanes or locations an Add Constraint rule covered in this run, and as how many rules when it is held For each. A filter follows the data, so the count changes when the scenario does. This message is for information.

What to do

Nothing to do if the count is what you meant. Otherwise check the filter against the scenario's tags and columns.

Where it comes from

Shown by Network Optimization. It is one of the messages about a node.