{{About|the April Fools' Day joke item|the standard item used to rename entities|Name Tag}}
{{joke feature}}
{{Infobox item
| title = Tag
| image = Tag.png
| renewable = Yes
| stackable = Yes (64)
}}
'''Tags''' and '''Bits''' are items exclusive to the [[Java Edition 23w13a or b|23w13a_or_b]] [[April Fools' Day jokes#2023|April Fools' joke]] snapshot from 2023. They are used to craft in-game representations of [[NBT format|NBT tags]].

== Obtaining ==
A [[stonecutter]] can be used to cut a [[name tag]] into either 16 "Name" or 16 "Tag" items. These can be cut into 16 Bit items each.

{{Stonecutting
|head=1
|showdescription=1
|Name Tag
|Name, 16; Tag, 16
|description=The resulting "Name" items must be named in an [[anvil]].
}}
{{Stonecutting
|showdescription=
|Name; Tag
|Bit, 16
|foot=1
}}

To be able to proceed from here the <code>nbt_crafting</code> vote must be approved. Bits can be used in a crafting table to craft Left Curly, Right Curly, Left Square, and Right Square.

A [[crafting table]] can be used to convert a "Tag" item into a "Byte Tag." The amount of [[stick]]s added to the crafting recipe specifies the value of the Byte, as a [[wikipedia:Signed number representations#Two's complement|signed 8-bit value]]. For example, a "Tag" and a full stack of sticks make a Byte with the value <code>64b</code>, while 255 sticks result in <code>-1b</code>. Only one of the sticks is consumed. Two Bytes can be crafted into a "Short Tag" (equivalent to 16 bit), two Shorts into an "Int Tag" (equivalent to 32 bit), and two Ints into a "Long Tag" (equivalent to 64 bit). Many other combinations that form either 16, 32, or 64 bit are possible. For example, two Shorts and an Int make a Long. When combining values, their digits are stuck together in the given order, e.g. <code>1b</code> and <code>0b</code> make <code>256s</code> (equivalent to 0100<sub>16</sub> in [[wikipedia:Hexadecimal|hexadecimal]]). Undoing any of these crafting actions in e.g. a stonecutter is not possible.

"Float" and "Double Tags" can be crafted by adding one or two [[boat]]s to any numeric tag. A "String Tag" is crafted with a "Tag" and a piece of [[string]].

{{Crafting
|head=1
|showdescription=1
|A1= Bit;    ; Bit; Bit |B1=    ; Bit; Bit; Bit
|A2=    ; Bit; Bit;     |B2= Bit;    ;    ; Bit
|A3= Bit;    ; Bit; Bit |B3=    ; Bit; Bit; Bit
|Output= Right Curly; Left Curly; Left Square; Right Square
|ignoreusage=1
}}
{{Crafting
|Tag
|String
|Output= String Tag
|description=String tags must be named in an [[anvil]] to set their value.
|ignoreusage=1
}}
{{Crafting
|Tag; Tag;   Tag
|;    Stick; Stick, 64
|;    ;      Stick, 63
|Output= Byte Tag; Byte Tag; Byte Tag
|description=Only 1 stick is consumed. 128 and more sticks make [[wikipedia:Signed number representations#Two's complement|two's complements]]:
128 sticks = <code>-128b</code><br>
129 sticks = <code>-127b</code><br>
⋮<br>
254 sticks = <code>-2b</code><br>
255 sticks = <code>-1b</code>
|ignoreusage=1
}}
{{Crafting
|Byte Tag; Byte Tag; Byte Tag
|Byte Tag; Byte Tag; Byte Tag
|        ; Byte Tag; Byte Tag
|        ; Byte Tag; Byte Tag
|        ;         ; Byte Tag
|        ;         ; Byte Tag
|        ;         ; Byte Tag
|        ;         ; Byte Tag
|Output= Short Tag; Int Tag; Long Tag
|description=Shorts and Ints can be combined the same way, even mixed.

Digits are appended, e.g. two <code>1b</code> tags make <code>257s</code> (0101<sub>16</sub> in [[wikipedia:Hexadecimal|hexadecimal]]).
|ignoreusage=1
}}
{{Crafting
|Byte Tag; Short Tag; Int Tag; Long Tag
|Any Boat; Any Boat; Any Boat; Any Boat
|Output= Float Tag; Float Tag; Float Tag; Float Tag
|ignoreusage=1
}}
{{Crafting
|Byte Tag; Short Tag; Int Tag; Long Tag
|Any Boat; Any Boat; Any Boat; Any Boat
|Any Boat; Any Boat; Any Boat; Any Boat
|Output= Double Tag; Double Tag; Double Tag; Double Tag
|ignoreusage=1
}}
{{Crafting
|Left Curly;  Left Curly
|Name;        Name
|Byte Tag;    Byte Tag
|Right Curly; Name |; Byte Tag | |; Name |; Byte Tag |; Right Curly
|Output= Compound Tag; Compound Tag
|description=Instead of Bytes any other tag can be used, including other compound tags.
|ignoreusage=1
}}
{{Crafting
|Left Square;  Left Square
|Byte Tag;     Byte Tag
|Right Square; Byte Tag |; Byte Tag |; Byte Tag |; Byte Tag |; Byte Tag |; Byte Tag |; Right Square
|Output= List Tag; List Tag
|description=Instead of Bytes any other tag can be used, including other list tags.
|ignoreusage=1
}}
{{Crafting
|Compound Tag; List Tag
|Compound Tag; List Tag
|Output= Compound Tag; List Tag
|description=Up to 9 can be combined.

When compound tags contain identical names, only the latest of the corresponding values is used.
|ignoreusage=1
}}
{{crafting
|ingredients=Any incomplete or <br>invalid combination of tags
|A1=Left Curly; Left Curly; Left Curly; Left Square; Left Square
|B1=Name; Name; Name; Byte Tag; Byte Tag
|C1=Byte Tag; ; String Tag; ;Byte Tag
|A2= ; Name; ; ; Byte Tag
|B2= ; Byte Tag; ; ; Byte Tag
|C2= ; ; ; ; Byte Tag
|A3= ; Name; ; ; Byte Tag
|B3= ; Byte Tag; ; ; Byte Tag
|C3= ; ; ; ;
|Output=Sssyntax Error
|description=If the player makes a mistake in the NBT structure, a Sssyntax error item will appear in the result slot with one of the following error messages in the tooltip:
*Expected { or [
*Expected either single or double
*Unexpected entries in when casting to float
*Unexpected value after closing bracket
*OH NO INTERNAL ERROR
*Can't add element of type <''type''> to list <''type''>
*Unexpected value in list: expected either tag or closing bracket
*Expected closing bracket
*Expected tag after name
*Expected name
*INTERNAL ERROR OH NO
*Unexpected value in compound tag: expected either name, tag or closing bracket
*Total number of bytes (<''number''> exceeds 8 <!-- This missing parenthesis is intentional -->
*Can't concatenate <''type''> with <''type''>
|ignoreusage=1
|foot=1
}}

"Name" and "String Tags" must be named in an [[anvil]] before they can be used. Unnamed Names and Strings always produce a "Sssyntax Error". None of the other tag items can be named.

All these items can be combined in a crafting table to form a short sequence of JSON code, as long as the resulting syntax is valid. For example: 
*A pair of Curlies that enclose a named "Name" item and some value, e.g. a Byte, create a "Compound Tag" with the content <code>{Example:0b}</code>.
**Because of the limited size of the crafting table only 3 name-value pairs can be put between Curlies at a time. Compound Tags of any length can be created by concatenating two or more Compound Tags.
**An empty pair of Curlies produces an empty Compound Tag with the content <code>{}</code>.
*A pair of Square brackets that enclose any number of values, e.g. 7 Bytes, create a "List Tag" with the content <code>[0b,0b,0b,0b,0b,0b,0b]</code>.
**Because of the limited size of the crafting table only 7 values can be put between Square brackets at a time. List Tags of any length can be created by concatenating two or more List Tags.
**An empty pair of Square brackets produces an empty List with the content <code>[]</code>.
**"Name" items cannot be used in a List.

The resulting Compound and List Tags can be used as values in other Compound and List Tags, as deeply nested as you want.

== Usage ==
Tags appear to have no further functionality. They cannot be eaten or placed in the world, except in an item frame, as each other item can. However, Compound Tags with values like <code>{Enchantments:[{id:"minecraft:sharpness",lvl:127b}]}</code> will show the [[Enchanting|enchantment]] glint and actually act accordingly when used.<ref>https://www.reddit.com/r/Minecraft/comments/129xdyl/i_figure_out_how_the_nbtcrafting_in_the_vote/</ref> This appears to work with many weapon and tool [[Enchanting#Summary of enchantments by item|enchantments]].

In theory, an extremely lucky <code>replace_recipe_output</code> vote can change the crafting recipe for compound tags to output something else. When cheats are enabled you can test this with a command like <code>/vote rule minecraft:replace_recipe_output approve {key:"minecraft:compound_tag",value:"minecraft:netherite_sword"}</code>. However, as long as this vote is approved no other compound tag can be crafted. Use <code>/vote rule minecraft:replace_recipe_output repeal *</code> to undo all recipe replacements.

In combination with the <code>midas_touch</code> vote tag items can be converted into [[gold ingot]]s. These retain their NBT data. When the world is loaded in another version of the game tag items disappear, but gold ingots persist.

== Trivia ==
*This implies that a [[name tag]] is 128 bit.
*Compound and list tags are special in so far that the value they show in their [[tooltip]] is not merely a property of the item, but their ''actual'' [[NBT format|NBT data]]. This is also the reason why naming them is disabled as that would mess up the NBT data.
*The snapshot also contains an [[History of textures/Unused textures|unused texture]] for an {{ItemLink|End Tag}}.

== History ==
{{HistoryTable
|{{HistoryLine|java}}
|{{HistoryLine||23w13a_or_b|[[File:Tag.png|32px]] Added tags.}}
}}

== Gallery ==
=== Renders ===
<gallery>
Tag.png|Tag
Bit.png|Bit
Byte Tag.png|Byte Tag
Compound Tag.png|Compound Tag
Double Tag.png|Double Tag
End Tag.png|End Tag
Float Tag.png|Float Tag
Int Tag.png|Int Tag
Left Curly.png|Left Curly
Left Square.png|Left Sqaure
List Tag.png|List Tag
Long Tag.png|Long Tag
Name (23w13a or b).png|Name
Right Curly.png|Right Curly
Right Square.png|Right Square
Short Tag.png|Short Tag
Sssyntax Error.png|Sssyntax Error
String Tag.png|String Tag
</gallery>

== References ==
{{reflist}}

== Navigation ==
{{Navbox items|Joke}}
{{Navbox jokes|23w13a or b}}

[[Category:Joke items]]
[[Category:Renewable resources]]

[[ja:Tag (アイテム)]]
[[pt:Tag (item)]]