---
id: "a-label"
kind: "glossary-term"
title: "A-label"
language: "en"
category: "DNS and technical foundations"
updated: "2026-10-04T14:01:23Z"
canonical: "https://tldlog.com/glossary/a-label/"
translations:
  es: "https://tldlog.com/es/glosario/etiqueta-a/"
  de: "https://tldlog.com/de/glossar/a-label/"
  fr: "https://tldlog.com/fr/glossaire/etiquette-a/"
  it: "https://tldlog.com/it/glossario/a-label/"
  pt-BR: "https://tldlog.com/pt/glossario/rotulo-a/"
  ru: "https://tldlog.com/ru/glossariy/a-metka/"
  zh-Hans: "https://tldlog.com/zh/cihui/a-biaoqian/"
---

# A-label

The ASCII form of one part of an internationalized domain name. It starts with xn-- followed by letters, digits and hyphens produced by Punycode. This is the form actually stored in the DNS and in registry systems, while people see the matching U-label.

## related terms

- [U-label](https://tldlog.com/glossary/u-label/)
- [Punycode](https://tldlog.com/glossary/punycode/)
- [IDN](https://tldlog.com/glossary/idn/)
- [IDNA2008](https://tldlog.com/glossary/idna2008/)
- [LDH](https://tldlog.com/glossary/ldh/)