Stack Groups let RRV collapse sets of near-identical items - like spawn eggs, minecarts, or potions - into a single expandable entry in the item list, so the index isn't cluttered with dozens of variants of the same item. Players can turn the feature on or off entirely from the "Stack Groups" client setting, and can enable, disable, or reprioritize individual groups from the "Configure Stack Groups" screen. Clicking a group's name in that screen opens a dropdown of its items that can be dragged to set the order they're displayed in. A group is only ever collapsed when 2 or more of its matching items are actually present in the index.

Via Resource Packs

Stack groups can be added by creating JSON files in assets/<namespace>/rrv/stack_groups. A group's id is derived from its file path (e.g. assets/rrv/rrv/stack_groups/foo/bar.json becomes rrv:foo/bar) unless overridden with id. The format is as follows:

• type: The type of group being defined. Defaults to rrv:group. See Group Types below.
• id: An optional override for the group's id.
• name: An optional translation key used as the group's display name. If omitted, RRV looks for a translation under stackgroup.rrv.<path>, falling back to the raw id.
• priority: An optional integer controlling match and sort order among groups. Higher priority groups are checked, and displayed, before lower priority ones. Defaults to 0.
• enabled: An optional boolean. Set to false to remove a previously defined group - see Disabling a Group.

Group Types

• rrv:group: A general-purpose group that can match items by any combination of:
  • contents: An array of items and/or tags to include, e.g. "minecraft:water", "#minecraft:logs", or { "type": "item"|"tag", "id": "..." }.
  • tag: A single item tag to match, e.g. "minecraft:logs". Can be paired with registry (defaults to minecraft:item) to match a tag from a different registry.
  • component: A single data component id, e.g. "minecraft:entity_data". Any item stack carrying this component is matched, regardless of its item id. Referencing a component that doesn't exist in the registry will throw an error.
  • regex / regexes: A single regular expression, or an array of them, matched against the item's full registry id.
  • exclusions: An array of items and/or tags (same format as contents) to always exclude from the group, even if they'd otherwise match.
• rrv:tag: Shorthand for a group matching a single item tag. Just needs tag.
• rrv:component: Shorthand for a group matching a single data component. Just needs component.
• rrv:regex: Shorthand for a group matching a single regular expression. Just needs regex.

At least one of contents, tag, component, or regex/regexes should be provided, otherwise the group will never match any items.

Examples

Grouping by Tag

Groups every item in the minecraft:logs tag under one entry.

Group file - assets/minecraft/rrv/stack_groups/logs.json

{
  "type": "rrv:tag",
  "tag": "minecraft:logs"
}

Grouping by Data Component

Groups every item stack carrying a given data component, regardless of item id. This is how RRV groups spawn eggs - every spawn egg variant carries a minecraft:entity_data component by default, so matching on the component catches all of them, including ones added by other mods, without listing each one individually.

Group file - assets/minecraft/rrv/stack_groups/spawn_eggs.json

{
  "type": "rrv:component",
  "component": "minecraft:entity_data"
}

Grouping Specific Items

contents accepts a mix of items and tags in the same list.

{
  "type": "rrv:group",
  "contents": [
    "minecraft:water",
    "#c:buckets",
    { "type": "item", "id": "minecraft:milk_bucket" }
  ]
}

Grouping by Regex

Groups every item whose registry id matches a pattern - useful for modded items that follow a naming convention.

{
  "type": "rrv:regex",
  "regex": "examplemod:.*_ingot"
}

Excluding Items From a Group

exclusions can be combined with any matching condition to carve out exceptions.

{
  "type": "rrv:group",
  "tag": "c:ores",
  "exclusions": [
    "minecraft:ancient_debris",
    "#examplemod:rare_ores"
  ]
}

Custom Display Name

name overrides the stackgroup.rrv.<path> fallback with a translation key of your choice.

Group file - assets/examplemod/rrv/stack_groups/example_ingots.json

{
  "type": "rrv:regex",
  "regex": "examplemod:.*_ingot",
  "name": "stackgroup.examplemod.ingots"
}

Lang file - assets/examplemod/lang/en_us.json

{
  "stackgroup.examplemod.ingots": "Ingots"
}

Priority

Higher priority groups are matched, and listed, before lower priority ones - useful when an item could otherwise belong to more than one group.

{
  "type": "rrv:tag",
  "tag": "examplemod:special_ingots",
  "priority": 10
}

Disabling a Group

Setting enabled to false removes a group entirely, including one shipped by RRV or another resource pack.

assets/minecraft/rrv/stack_groups/logs.json

{
  "enabled": false
}

Built-In Groups

RRV ships several groups with matching logic that can't be expressed in JSON: Minecarts, Pressure Plates, Infested Blocks, Copper Blocks, and Coral. These are always active and can't be removed with an enabled: false override: instead, they can be disabled individually from the "Configure Stack Groups" screen in the client settings.

Tag Groups From Recipes

Whenever a recipe shows an ingredient represented by an item tag, RRV adds a small button to quickly enable or disable a rrv:tag stack group for that tag directly from the recipe screen, without needing to make a resource pack.