But how are backpacks added then to soldiers? There's a config entry for whether or not they can carry a backpack, but I'm unsure about where it says what kind if any of backpack they'll be carrying. If they are added with e.g. addweapon, then they're weapons, no? If they're added with their own command, then I'm not so sure about the description.ext.
Since you're a campaign scripter, have you tried manually adding backpacks (i.e. as the player go and drop a backpack or two into a crate) to an ammocrate, then saving the ammocrate to the campaign weapon/magazine pool, and then see if they show up in future missions? If they do, then there just HAS to be some way to add them to the pool, I'd say...
Wolfrug out.