emacs/etc/charsets/README

# README file for charset mapping files in this directory.

# Copyright (C) 2003-2012  Free Software Foundation, Inc.
# Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
#   National Institute of Advanced Industrial Science and Technology (AIST)
#   Registration Number H13PRO009

# This file is part of GNU Emacs.

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# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

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# GNU General Public License for more details.

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(1) Format of mapping files

Each line contains a code point and the corresponding Unicode
character code separated by a space.  Both code points and Unicode
character codes are in hexadecimal preceded by "0x".  Comments may be
used, starting with "#".  Code ranges may also be used, with
(inclusive) start and end code points separated by "-" followed by the
Unicode of the start of the range

Examples:
0xA0 0x00A0  # no-break space

0x8141-0x8143 0x4E04 # map onto a Unicode range


(2) Source of mapping files

All mapping files are generated automatically from data files freely
available on the Internet (e.g. glibc/localedata/charmaps").  See the
file ../../admin/charsets/mapfiles/README for the detail.