new hook

       [HookMethod("GetShortNameBackpack")]
        private List<string> GetShortNameBackpack()
        {
            return config.f_BackpacksByShortname.Keys.ToList();
        }

        [HookMethod("GetHaveBackpack")]
        private bool GetHaveBackpack(BasePlayer player)
        {
            if (player != null)
            {
                if (!Instance.permission.UserHasPermission(player.UserIDString, PERM_BACKPACKSLIMIT_BYPASS))
                {
                    int backpacksAmount = 0;
                    foreach (var item in player.inventory.containerWear.itemList.Concat(player.inventory.containerBelt.itemList.Concat(player.inventory.containerMain.itemList)))
                    {
                        if (config.ContainsBackpack(item.info.shortname))
                            backpacksAmount++;

                        if (backpacksAmount >= config.GeneralSettings.MaxBackpacksAmount)
                        {
                            return true;
                        }

                    }

                    return false;
                }
            }
            return false;
        }

Please add these hooks in the next update so that we don't have to constantly add them. We're using your plugin, just tweaking it a little bit.

Also, it would be great if you added some implementations in the plugin.

Quote

• allow empty backpacks to be placed in the player's inventory, but prohibit the storage of filled backpacks. for example, this is necessary if someone implements the crafting of backpacks, like me, for example.