I'm sure most of you have some kind of system already, but here's another: If you get any collection of ammo cans, you certainly don't want to open them up each time to see what's inside. So, labeling them is a must. If you have any of that blue painter's tape lying around, use that. It's easy to come off and waterproof. I use a metallic Sharpie and the lettering really stands out.