Bukkit

allWorlds:
  default:
    MIN: -1 // See the definitions at the top of this page for details on how to use these
    MAX: -1 // They can be set underneath default or any playerName, groupName, or inventoryName
  player:
    playerName:
  group:
    groupName:
  inventory:
    inventoryName:

allWorlds:
  default: // Everything defined here will be applied to every player, group, inventory within every world UNLESS overridden below
    snow_ball: 32 // allows snow balls to stack to 32
    arrow: 32 // You can add as many materials as you want
  inventory:
    chest:
      snow_ball: 64 // Overrides the default setting to allow snow balls to stack to 64 in chests
    ender_chest:
      snow_ball: 4 // Overrides ender chests to only allow snow balls to stack to 4

allWorlds:
  default:
    MIN: -1
    MAX -1
  player:
    haveric: // for setting up the player, just set the name here, it will get replaced with a uuid and an original name as seen below
      dirt: 100
    fa2ebad5-7014-4e60-90fa-321236fdde9f: // autogenerated uuid
      original-name: haveric // autogenerated from the original setting/uuid
      dirt: 100
  group:
    admin:
      MIN: 100 // Sets all items whose stacks are below 100 (with vanilla, that would be all items) to stack to 100.
      snow_ball: 64
  inventory:
    chest:
      cobblestone: 16
    ender_chest:
      disabled: true // Disables Ender Chests from being affected by StackableItems for all worlds.
testWorld:
  default:
    MIN: -1
    MAX: -1
  group: 
    knights,archers: // Apply configs to multiple groups with a comma
      tnt: 0 // Disables tnt
  inventory:
    chest,dispenser: // Apply configs to multiple inventories with a comma
      arrow: 100
flatland,creative: // Apply configs to multiple worlds with a comma
  default:
    MAX: 16 // Restricts all items to have at most 16 per stack. Will not affect any items with stacks below 16.

allWorlds:
  default:
    MIN: -1 // -1 will use default vanilla values.
    MAX: -1 
    tnt: 0 // Disables picking up and crafting of tnt
    dirt: 100 // Override dirt to stack to 100
    cobblestone: 127 // Override cobble to 127
    '5': 5 // You can use the data values (with or without quotes, it will add the quotes if you don't), Overrides wood planks to 5
  admin: // Use permission group names to affect only group members (the group also needs the permission node: stackableitems.stack)
    tnt: -1 // Gives all admins normal use of tnt overriding the disable in default
  haveric: // Use any player's name to give them specific overrides
    MIN: 100 // You can override individual players if you want to give them different stacking amounts. In this case, I'll be able to stack anything to 100
    MAX: -1 // If MIN is >= 64, max won't do anything as all values will be higher already and nothing can be brought down from vanilla
  Chest: // any vanilla inventory can be overridden as well
    MIN: -1
    MAX: -1
    diamond_sword: 10 // Allows stacking of diamond swords to 10 only in chests
    cobblestone: 100 // Allows cobble to be stacked to 100 in chests.
rpg: // Create specific stacking rules per world, in this case for the world named "rpg"
  default:
    MIN: 32 // All items on rpg will stack to at least 32 (Snowballs will stack to 32, dirt will stay at 64)
    MAX: 48 // All items on rpg will stack to a max of 48 (Snowballs will stay at 32, dirt will stack to 48)
    373: 20 // Override all potions to stack to 20
    torch: 40 // Override torches to stack to 40
    dirt: infinite // Will not consume dirt when placing, but will still collect it.
  Dispenser:
    iron_sword: 3 // Override iron swords to stack to 3 in dispensers.

Sets all items to a max of 10 except for snowballs which can be up to 100
All items Max: 10
SNOW_BALL: 100

Sets all items to normal except snowballs can be up to 64
All items Max: -1
SNOW_BALL: 64

Sets all steps to 20 except for cobble steps which can be up to 40 and all other items are normal
All items Max: -1
STEP: 20
STEP 3: 40

Sets all wool to 20 except white wool which is 30 and all other items are normal
All items Max: -1
35: 20
35 0: 30