LACE: Length-based ASCII Compatible Encoding for IDN

Document Type Expired Internet-Draft (idn WG)
Authors Mark Davis  , Paul Hoffman 
Last updated 2001-01-05
Stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Expired & archived
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Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
Consensus Boilerplate Unknown
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document describes a transformation method for representing non-ASCII characters in host name parts in a fashion that is completely compatible with the current DNS. It is a potential candidate for an ASCII-Compatible Encoding (ACE) for internationalized host names, as described in the comparison document from the IETF IDN Working Group. This method is based on the observation that many internationalized host name parts will have a few substrings from a small number of rows of the ISO 10646 repertoire. Run-length encoding for these types of host names will be fairly compact, and is fairly easy to describe.


Mark Davis (
Paul Hoffman (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)