# Metacharacters

Metacharacters are used to reference one of the four reserved
delimiters that D3 uses within its item structure.

The four metacharacters include:

- Attribute marks

- Value marks

- Subvalue marks

- Segment marks

## See also

- [Attribute](https://d3codex.com/definitions/attribute/)
- [Attribute mark](https://d3codex.com/definitions/attribute-mark/)
- [dump command](https://d3codex.com/tcl/dump-command/)
- [Segment mark](https://d3codex.com/definitions/segment-mark/)
- [Start buffer mark](https://d3codex.com/definitions/start-buffer-mark/)
- [Subvalue](https://d3codex.com/definitions/subvalue/)
- [Subvalue mark](https://d3codex.com/definitions/subvalue-mark/)
- [Value](https://d3codex.com/definitions/value/)
- [Value mark](https://d3codex.com/definitions/value-mark/)

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Source: https://d3codex.com/definitions/metacharacters/ - part of the D3Codex reference.