It's just unique spot to hold each part. There are 8 trays with 100 pockets each, so if you wanted to know a specific component's electrical properties, I could

It's just unique spot to hold each part. There are 8 trays with 100 pockets each, so if you wanted to know a specific component's electrical properties, I could look up which tray and pocket it's in and measure it. Or if I get around to measuring all of them, I can push that data into the boardview itself.