# Constraints Window

The constraints window is used to define rules governing the random selection of rack combinations. This is explained more in the constraints table documentation.

This window contains a list of the defined constraints in the database. Double-clicking on one of them opens up a window full of checkboxes and rack names.

This window is used to select which racks are used in the constraint. Check the boxes of the racks that are required to be selected, and the racks which will (if selected) trigger their selection.

To actually use the constraints, in the window for a particular run hit the "constraints" button. A window like this will appear with a list of all the constraints, and you can check the ones you want to apply to this run.