Issue link: https://resources.pcb.cadence.com/i/1541046
13. Keeping Height and Keep-In/Keep-Out Constraints Visible PCB Assemblies Often Fit Into Mechanical Enclosures, Under Shields, Or Near Moving Parts. Ignoring Height And Keep-In/Keep- Out Zones Can Lead To Collisions With The Case, Mounting Failures, Blocked Airflow, Or Even Short Circuits And Catastrophic Field Failures. Tall Parts That Aren't Planned For Can Prevent Enclosure Closure, Interfere With Adjacent PCBs, Or Complicate Assembly And Test. Properly Visualizing And Enforcing These Constraints From The Start Is Critical For First-Pass Success, Mechanical Fit, And Reliability. When And Where To Apply Apply Height And Keepout Constraints Before Or During Initial Placement, Before Any Tall Part Is Locked Down, And Any Time The Mechanical Or Industrial Design Changes. This Is Mandatory For All Products Going Into An Enclosure, Using Shields, Or Intended For High-Density Rack, Automotive, Or Portable Applications. In OrCAD X PCB Layout, a keep-out violation happens when a trace, via, or component is placed in an area that has been defined as a keep-out region. Keep-outs are design rule boundaries that tell the tool "nothing should be routed or placed here".