Minecraft – the definition of a “data tag”

minecraft-java-edition

I have been reading about using command blocks, and I come across the term "data tag" a lot. Can anyone explain what this is?

For example:

/summon <EntityName> [x] [y] [z] [dataTag]

Best Answer

The data tag is a piece of text that allows you to assign NBT (Named Binary Tag, see here) data to items or entities.

There are a number of different commands that can be used with data tags to assign NBT data. For more information, check out this post on the Minecraft subreddit.

Related Solutions

Minecraft – Summon an item frame with custom item which have data on it

The Damage tag holds the metadata value of the item:

/summon ItemFrame 2019 32 1060 {Facing:3,Item:{id:"minecraft:skull",Damage:5,Count:1}}

Since 1.8, you should not have been using numerical IDs in NBT data. Since 1.7, using numerical IDs in command syntax presented you with a warning to not use name IDs.

Minecraft – How to fix “unbalanced brackets” in the data tag

The easiest way to find mismatched braces is to expand the command into a multi-line format with properly indented lines. This makes it easier to find errors and subsequently fix them.

A nifty little tool to automatically format your data tags can be found at http://jsonviewer.stack.hu/. Using the Format and Remove White Space buttons, you can expand or collapse your command, respectively. Using the sample data tag given in the questions, we can turn this

{Profession:3,Career:2,Offers:{Recipes:[{buy:{id:minecraft:diamond,Count:6b}},sell:{id:minecraft:diamond_hoe,tag:{ench:[{id:16s,lvl:10s}]}]}}

into this

{
  Profession: 3,
  Career: 2,
  Offers: {
    Recipes: [
      {
        buy: {
          id: minecraft: diamond,
          Count: 6b
        }
      },
      sell: {
        id: minecraft: diamond_hoe,
        tag: {
          ench: [
            {
              id: 16s,
              lvl: 10s
            }
          ]
        }
      ]
    }
  }

Now all that is left is compare the opening and closing brackets at each indentation level. You can see that there is no closing bracket at the last indentation level, the last bracket is indented once, showing us that there is a closing bracket missing on some level.

If you check all the tags starting at the top, you can see that there's a problem with the sell tag: There's a closing square bracket instead of a curly bracket on that indentation level. To make this even more visible, we can copy-paste our data tag into an advanced text editor like Notepad++, which highlights matching brackets for us:

Have the missing curly bracket problem:

Here it is immediately apparent that a closing curly bracket is needed for the sell tag.

Without the missing bracket: