I'm making a custom part for the Cree MX3S high power LED's. The attached picture shows the dimensions of the pads and heat sink die. I used the hole tool to add the thermal vias and made them 0.2mm in diameter even though the data sheet doesn't mention the diameter of these holes. On the data sheet for the part dimensions I see these lines marked in the photo with red arrows. I didn't know what they were for so I just used them to show the part on the PCB (the tplace layer). The diagonal line is to mark the cathode of the LED. Can someone tell me what those lines are for?