The first one is a loot from a vanilla block. As you imagine it will drop a defusing_bomb cardor a homework cardwhen the player breaks a NETHER_QUARTZ_ORE.
These drops are decided by the pluginbased on chance you set.
The second one is an ItemsAdder custom block and is called ruby_ore (you can call them as you prefer), this will drop a clean_it card when you break a custom block of type itemsadder:ruby_ore with a minimum amount of 1 and maximum amount of 2 with 100% chance.
Special property: drop_only_first
This allows you to stop the plugin from dropping each of the items that succeed into extracting a correct chance to be dropped.
WARNING: this would make your items harder to be dropped.
Ignore fortune enchant
You can make a loot ignore fortune enchant by adding the ignore_fortune property.
Other types of loots
As I said before there are other types of loots: mobs and fishing.
These are some examples:
Fishing
Mobs
Custom mobs loots
In order to let ItemsAdder drop an item based on when you kill a custom mob (created with ItemsAdder) you have to use the metadata attribute. Example:
As you can see I set ItemsAdderMob attribute and specified my custom mob namespace:id (in this example I used the creaturesplus:soul mob)
Villager professions
(and any other NBT attribute you want to match)
As you can see I set profession attribute and specified the NBT attribute path, which in this case is VillagerData.profession.
Then I set value to minecraft:farmer, this tells ItemsAdder to match only villagers with attribute VillagerData.profession set to minecraft:farmer.
The type attribute of nbt and metadata are really important, don't forget them or matches could not occur.