Internet-Draft Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation
Expires in six months 4 June 2004
LDAP: Internationalized String Preparation
<draft-ietf-ldapbis-strprep-04.txt>
Status of this Memo
This document is intended to be published as a Standard Track RFC.
Distribution of this memo is unlimited. Technical discussion of this
document will take place on the IETF LDAP Revision Working Group
mailing list <ietf-ldapbis@openldap.org>. Please send editorial
comments directly to the editor <Kurt@OpenLDAP.org>.
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Abstract
The previous Lightweight Directory Access Protocol (LDAP) technical
specifications did not precisely define how character string matching
is to be performed. This led to a number of usability and
interoperability problems. This document defines string preparation
algorithms for character-based matching rules defined for use in LDAP.
Conventions and Terms
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14 [RFC2119].
Character names in this document use the notation for code points and
names from the Unicode Standard [Unicode]. For example, the letter
"a" may be represented as either <U+0061> or <LATIN SMALL LETTER A>.
In the lists of mappings and the prohibited characters, the "U+" is
left off to make the lists easier to read. The comments for character
ranges are shown in square brackets (such as "[CONTROL CHARACTERS]")
and do not come from the standard.
Note: a glossary of terms used in Unicode can be found in [Glossary].
Information on the Unicode character encoding model can be found in
[CharModel].
The term "combining mark", as used in this specification, refers to
any Unicode [Unicode] code point which has a mark property (Mn, Mc,
Me). Appendix C provides a complete list of combining marks.
1. Introduction
1.1. Background
A Lightweight Directory Access Protocol (LDAP) [Roadmap] matching rule
[Syntaxes] defines an algorithm for determining whether a presented
value matches an attribute value in accordance with the criteria
defined for the rule. The proposition may be evaluated to True,
False, or Undefined.
True - the attribute contains a matching value,
False - the attribute contains no matching value,
Undefined - it cannot be determined whether the attribute contains
a matching value or not.
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For instance, the caseIgnoreMatch matching rule may be used to compare
whether the commonName attribute contains a particular value without
regard for case and insignificant spaces.
1.2. X.500 String Matching Rules
"X.520: Selected attribute types" [X.520] provides (amongst other
things) value syntaxes and matching rules for comparing values
commonly used in the Directory. These specifications are inadequate
for strings composed of Unicode [Unicode] characters.
The caseIgnoreMatch matching rule [X.520], for example, is simply
defined as being a case insensitive comparison where insignificant
spaces are ignored. For printableString, there is only one space
character and case mapping is bijective, hence this definition is
sufficient. However, for Unicode string types such as
universalString, this is not sufficient. For example, a case
insensitive matching implementation which folded lower case characters
to upper case would yield different different results than an
implementation which used upper case to lower case folding. Or one
implementation may view space as referring to only SPACE (U+0020), a
second implementation may view any character with the space separator
(Zs) property as a space, and another implementation may view any
character with the whitespace (WS) category as a space.
The lack of precise specification for character string matching has
led to significant interoperability problems. When used in
certificate chain validation, security vulnerabilities can arise. To
address these problems, this document defines precise algorithms for
preparing character strings for matching.
1.3. Relationship to "stringprep"
The character string preparation algorithms described in this document
are based upon the "stringprep" approach [StringPrep]. In
"stringprep", presented and stored values are first prepared for
comparison and so that a character-by-character comparison yields the
"correct" result.
The approach used here is a refinement of the "stringprep"
[StringPrep] approach. Each algorithm involves two additional
preparation steps.
a) prior to applying the Unicode string preparation steps outlined in
"stringprep", the string is transcoded to Unicode;
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b) after applying the Unicode string preparation steps outlined in
"stringprep", characters insignificant to the matching rules are
removed.
Hence, preparation of character strings for X.500 matching involves
the following steps:
1) Transcode
2) Map
3) Normalize
4) Prohibit
5) Check Bidi (Bidirectional)
6) Insignificant Character Removal
These steps are described in Section 2.
1.4. Relationship to the LDAP Technical Specification
This document is a integral part of the LDAP technical specification
[Roadmap] which obsoletes the previously defined LDAP technical
specification [RFC3377] in its entirety.
This document details new LDAP internationalized character string
preparation algorithms used by [Syntaxes] and possible other technical
specifications defining LDAP syntaxes and/or matching rules.
1.5. Relationship to X.500
LDAP is defined [Roadmap] in X.500 terms as an X.500 access mechanism.
As such, there is a strong desire for alignment between LDAP and X.500
syntax and semantics. The character string preparation algorithms
described in this document are based upon "Internationalized String
Matching Rules for X.500" [XMATCH] proposal to ITU/ISO Joint Study
Group 2.
2. String Preparation
The following six-step process SHALL be applied to each presented and
attribute value in preparation for character string matching rule
evaluation.
1) Transcode
2) Map
3) Normalize
4) Prohibit
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5) Check bidi
6) Insignificant Character Removal
Failure in any step causes the assertion to evaluate to Undefined.
This process is intended to act upon non-empty character strings. If
the string to prepare is empty, this process is not applied and the
assertion is evaluated to Undefined.
The character repertoire of this process is Unicode 3.2 [Unicode].
2.1. Transcode
Each non-Unicode string value is transcoded to Unicode.
TeletexString [X.680][T.61] values are transcoded to Unicode as
described in Appendix A.
PrintableString [X.680] value are transcoded directly to Unicode.
UniversalString, UTF8String, and bmpString [X.680] values need not be
transcoded as they are Unicode-based strings (in the case of
bmpString, a subset of Unicode).
The output is the transcoded string.
2.2. Map
SOFT HYPHEN (U+00AD) and MONGOLIAN TODO SOFT HYPHEN (U+1806) code
points are mapped to nothing. COMBINING GRAPHEME JOINER (U+034F) and
VARIATION SELECTORs (U+180B-180D, FF00-FE0F) code points are also
mapped to nothing. The OBJECT REPLACEMENT CHARACTER (U+FFFC) is
mapped to nothing.
CHARACTER TABULATION (U+0009), LINE FEED (LF) (U+000A), LINE
TABULATION (U+000B), FORM FEED (FF) (U+000C), CARRIAGE RETURN (CR)
(U+000D), and NEXT LINE (NEL) (U+0085) are mapped to SPACE (U+0020).
All other control code (e.g., Cc) points or code points with a control
function (e.g., Cf) are mapped to nothing. The following is a
complete list of these code points: U+0000-0008, 000E-001F, 007F-0084,
0086-009F, 06DD, 070F, 180E, 200C-200F, 202A-202E, 2060-2063,
206A-206F, FEFF, FFF9-FFFB, 1D173-1D17A, E0001, E0020-E007F.
ZERO WIDTH SPACE (U+200B) is mapped to nothing. All other code points
with Separator (space, line, or paragraph) property (e.g, Zs, Zl, or
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Zp) are mapped to SPACE (U+0020). The following is a complete list of
these code points: U+0020, 00A0, 1680, 2000-200A, 2028-2029, 202F,
205F, 3000.
For case ignore, numeric, and stored prefix string matching rules,
characters are case folded per B.2 of [StringPrep].
The output is the mapped string.
2.3. Normalize
The input string is be normalized to Unicode Form KC (compatibility
composed) as described in [UAX15]. The output is the normalized
string.
2.4. Prohibit
All Unassigned code points are prohibited. Unassigned code points are
listed in Table A.1 of [StringPrep].
Characters which, per Section 5.8 of [Stringprep], change display
properties or are deprecated are prohibited. These characters are are
listed in Table C.8 of [StringPrep].
Private Use code points are prohibited. These characters are listed
in Table C.3 of [StringPrep].
All non-character code points are prohibited. These code points are
listed in Table C.4 of [StringPrep].
Surrogate codes are prohibited. These characters are listed in Table
C.5 of [StringPrep].
The REPLACEMENT CHARACTER (U+FFFD) code point is prohibited.
The step fails if the input string contains any prohibited code point.
Otherwise, the output is the input string.
2.5. Check bidi
This step fails if the input string does not conform to the the
bidirectional character restrictions detailed in 6 of [Stringprep].
Otherwise, the output is the input string.
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2.6. Insignificant Character Removal
In this step, characters insignificant to the matching rule are to be
removed. The characters to be removed differ from matching rule to
matching rule.
Section 2.6.1 applies to case ignore and exact string matching.
Section 2.6.2 applies to numericString matching.
Section 2.6.3 applies to telephoneNumber matching.
2.6.1. Insignificant Space Removal
For the purposes of this section, a space is defined to be the SPACE
(U+0020) code point followed by no combining marks.
NOTE - The previous steps ensure that the string cannot contain any
code points in the separator class, other than SPACE (U+0020).
If the input string consists entirely of spaces or is empty, the
output is a string consisting of exactly one space (e.g. " ").
Otherwise, the following spaces are removed:
- leading spaces (i.e. those preceding the first character that is
not a space);
- trailing spaces (i.e. those following the last character that is
not a space);
- multiple consecutive spaces (these are taken as equivalent to a
single space character).
For example, removal of spaces from the Form KC string:
"<SPACE><SPACE>foo<SPACE><SPACE>bar<SPACE><SPACE>"
would result in the output string:
"foo<SPACE>bar"
and the Form KC string:
"<SPACE><SPACE><SPACE>"
would result in the output string:
"<SPACE>".
2.6.2. numericString Insignificant Character Removal
For the purposes of this section, a space is defined to be the SPACE
(U+0020) code point followed by no combining marks.
All spaces are regarded as not significant. If the input string
consists entirely of spaces or is empty, the output is a string
consisting of exactly one space (e.g. " "). Otherwise, all spaces are
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to be removed.
For example, removal of spaces from the Form KC string:
"<SPACE><SPACE>123<SPACE><SPACE>456<SPACE><SPACE>"
would result in the output string:
"123456"
and the Form KC string:
"<SPACE><SPACE><SPACE>"
would result in the output string:
"<SPACE>".
2.6.3. telephoneNumber Insignificant Character Removal
For the purposes of this section, a hyphen is defined to be
HYPHEN-MINUS (U+002D), ARMENIAN HYPHEN (U+058A), HYPHEN (U+2010),
NON-BREAKING HYPHEN (U+2011), MINUS SIGN (U+2212), SMALL HYPHEN-MINUS
(U+FE63), or FULLWIDTH HYPHEN-MINUS (U+FF0D) code point followed by no
combining marks and a space is defined to be the SPACE (U+0020) code
point followed by no combining marks.
All hyphens and spaces are considered insignificant. If the string
contains only spaces and hyphens or is empty, then the output is a
string consisting of one space. Otherwise, all hyphens and spaces are
removed.
For example, removal of hyphens and spaces from the Form KC string:
"<SPACE><HYPHEN>123<SPACE><SPACE>456<SPACE><HYPHEN>"
would result in the output string:
"123456"
and the Form KC string:
"<HYPHEN><HYPHEN><HYPHEN>"
would result in the output string:
"<SPACE>".
3. Security Considerations
"Preparation for International Strings ('stringprep')" [StringPrep]
security considerations generally apply to the algorithms described
here.
4. Contributors
Appendix A and B of this document were authored by Howard Chu
<hyc@symas.com> of Symas Corporation (based upon information provided
in RFC 1345).
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5. Acknowledgments
The approach used in this document is based upon design principles and
algorithms described in "Preparation of Internationalized Strings
('stringprep')" [StringPrep] by Paul Hoffman and Marc Blanchet. Some
additional guidance was drawn from Unicode Technical Standards,
Technical Reports, and Notes.
This document is a product of the IETF LDAP Revision (LDAPBIS) Working
Group.
6. Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
Email: Kurt@OpenLDAP.org
7. References
[[Note to the RFC Editor: please replace the citation tags used in
referencing Internet-Drafts with tags of the form RFCnnnn.]]
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14 (also RFC 2119), March 1997.
[Roadmap] Zeilenga, K. (editor), "LDAP: Technical Specification
Road Map", draft-ietf-ldapbis-roadmap-xx.txt, a work in
progress.
[StringPrep] Hoffman P. and M. Blanchet, "Preparation of
Internationalized Strings ('stringprep')",
draft-hoffman-rfc3454bis-xx.txt, a work in progress.
[Syntaxes] Legg, S. (editor), "LDAP: Syntaxes and Matching Rules",
draft-ietf-ldapbis-syntaxes-xx.txt, a work in progress.
[Unicode] The Unicode Consortium, "The Unicode Standard, Version
3.2.0" is defined by "The Unicode Standard, Version 3.0"
(Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5),
as amended by the "Unicode Standard Annex #27: Unicode
3.1" (http://www.unicode.org/reports/tr27/) and by the
"Unicode Standard Annex #28: Unicode 3.2"
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(http://www.unicode.org/reports/tr28/).
[UAX15] Davis, M. and M. Duerst, "Unicode Standard Annex #15:
Unicode Normalization Forms, Version 3.2.0".
<http://www.unicode.org/unicode/reports/tr15/tr15-22.html>,
March 2002.
[X.680] International Telecommunication Union -
Telecommunication Standardization Sector, "Abstract
Syntax Notation One (ASN.1) - Specification of Basic
Notation", X.680(1997) (also ISO/IEC 8824-1:1998).
[T.61] CCITT (now ITU), "Character Repertoire and Coded
Character Sets for the International Teletex Service",
T.61, 1988.
7.2. Informative References
[X.500] International Telecommunication Union -
Telecommunication Standardization Sector, "The Directory
-- Overview of concepts, models and services,"
X.500(1993) (also ISO/IEC 9594-1:1994).
[X.501] International Telecommunication Union -
Telecommunication Standardization Sector, "The Directory
-- Models," X.501(1993) (also ISO/IEC 9594-2:1994).
[X.520] International Telecommunication Union -
Telecommunication Standardization Sector, "The
Directory: Selected Attribute Types", X.520(1993) (also
ISO/IEC 9594-6:1994).
[Glossary] The Unicode Consortium, "Unicode Glossary",
<http://www.unicode.org/glossary/>.
[CharModel] Whistler, K. and M. Davis, "Unicode Technical Report
#17, Character Encoding Model", UTR17,
<http://www.unicode.org/unicode/reports/tr17/>, August
2000.
[XMATCH] Zeilenga, K., "Internationalized String Matching Rules
for X.500", draft-zeilenga-ldapbis-strmatch-xx.txt, a
work in progress.
[RFC1345] Simonsen, K., "Character Mnemonics & Character Sets",
RFC 1345, June 1992.
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Appendix A. Teletex (T.61) to Unicode
This appendix defines an algorithm for transcoding [T.61] characters
to [Unicode] characters for use in string preparation for LDAP
matching rules. This appendix is normative.
The transcoding algorithm is derived from the T.61-8bit definition
provided in [RFC1345]. With a few exceptions, the T.61 character
codes from x00 to x7f are equivalent to the corresponding [Unicode]
code points, and their values are left unchanged by this algorithm.
E.g. the T.61 code x20 is identical to (U+0020). The exceptions are
for these T.61 codes that are undefined: x23, x24, x5c, x5e, x60, x7b,
x7d, and x7e.
The codes from x80 to x9f are also equivalent to the corresponding
Unicode code points. This is specified for completeness only, as
these codes are control characters, and will be mapped to nothing in
the LDAP String Preparation Mapping step.
The remaining T.61 codes are mapped below in Table A.1. Table
positions marked "??" are undefined.
Input strings containing undefined T.61 codes SHALL produce an
Undefined matching result. For diagnostic purposes, this algorithm
does not fail for undefined input codes. Instead, undefined codes in
the input are mapped to the Unicode REPLACEMENT CHARACTER (U+FFFD).
As the LDAP String Preparation Prohibit step disallows the REPLACEMENT
CHARACTER from appearing in its output, this transcoding yields the
desired effect.
Note: RFC 1345 listed the non-spacing accent codepoints as residing in
the range starting at (U+E000). In the current Unicode
standard, the (U+E000) range is reserved for Private Use, and
the non-spacing accents are in the range starting at (U+0300).
The tables here use the (U+0300) range for these accents.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
a0| 00a0 | 00a1 | 00a2 | 00a3 | 0024 | 00a5 | 0023 | 00a7 |
a8| 00a8 | ?? | ?? | 00ab | ?? | ?? | ?? | ?? |
b0| 00b0 | 00b1 | 00b2 | 00b3 | 00d7 | 00b5 | 00b6 | 00b7 |
b8| 00f7 | ?? | ?? | 00bb | 00bc | 00bd | 00be | 00bf |
c0| ?? | 0300 | 0301 | 0302 | 0303 | 0304 | 0306 | 0307 |
c8| 0308 | ?? | 030a | 0327 | 0332 | 030b | 0328 | 030c |
d0| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
d8| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
e0| 2126 | 00c6 | 00d0 | 00aa | ?? | 0126 | 0132 | 013f |
e8| 0141 | 00d8 | 0152 | 00ba | 00de | 0166 | 014a | 0149 |
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f0| 0138 | 00e6 | 0111 | 00f0 | 0127 | 0131 | 0133 | 0140 |
f8| 0142 | 00f8 | 0153 | 00df | 00fe | 0167 | 014b | ?? |
--+------+------+------+------+------+------+------+------+
Table A.1: Mapping of 8-bit T.61 codes to Unicode
T.61 also defines a number of accented characters that are formed by
combining an accent prefix followed by a base character. These
prefixes are in the code range xc1 to xcf. If a prefix character
appears at the end of a string, the result is undefined. Otherwise
these sequences are mapped to Unicode by substituting the
corresponding non-spacing accent code (as listed in Table A.1) for the
accent prefix, and exchanging the order so that the base character
precedes the accent.
Appendix B. Additional Teletex (T.61) to Unicode Tables
All of the accented characters in T.61 have a corresponding code point
in Unicode. For the sake of completeness, the combined character
codes are presented in the following tables. This is informational
only; for matching purposes it is sufficient to map the non-spacing
accent and exchange the order of the character pair as specified in
Appendix A. This appendix is informative.
B.1. Combinations with SPACE
Accents may be combined with a <SPACE> to generate the accent by
itself. For each accent code, the result of combining with <SPACE> is
listed in Table B.1.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
c0| ?? | 0060 | 00b4 | 005e | 007e | 00af | 02d8 | 02d9 |
c8| 00a8 | ?? | 02da | 00b8 | ?? | 02dd | 02db | 02c7 |
--+------+------+------+------+------+------+------+------+
Table B.1: Mapping of T.61 Accents with <SPACE> to Unicode
B.2. Combinations for xc1: (Grave accent)
T.61 has predefined characters for combinations with A, E, I, O, and
U. Unicode also defines combinations for N, W, and Y. All of these
combinations are present in Table B.2.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c0 | ?? | ?? | ?? | 00c8 | ?? | ?? |
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48| ?? | 00cc | ?? | ?? | ?? | ?? | 01f8 | 00d2 |
50| ?? | ?? | ?? | ?? | ?? | 00d9 | ?? | 1e80 |
58| ?? | 1ef2 | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e0 | ?? | ?? | ?? | 00e8 | ?? | ?? |
68| ?? | 00ec | ?? | ?? | ?? | ?? | 01f9 | 00f2 |
70| ?? | ?? | ?? | ?? | ?? | 00f9 | ?? | 1e81 |
78| ?? | 1ef3 | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.2: Mapping of T.61 Grave Accent Combinations
B.3. Combinations for xc2: (Acute accent)
T.61 has predefined characters for combinations with A, E, I, O, U, Y,
C, L, N, R, S, and Z. Unicode also defines G, K, M, P, and W. All of
these combinations are present in Table B.3.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c1 | ?? | 0106 | ?? | 00c9 | ?? | 01f4 |
48| ?? | 00cd | ?? | 1e30 | 0139 | 1e3e | 0143 | 00d3 |
50| 1e54 | ?? | 0154 | 015a | ?? | 00da | ?? | 1e82 |
58| ?? | 00dd | 0179 | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e1 | ?? | 0107 | ?? | 00e9 | ?? | 01f5 |
68| ?? | 00ed | ?? | 1e31 | 013a | 1e3f | 0144 | 00f3 |
70| 1e55 | ?? | 0155 | 015b | ?? | 00fa | ?? | 1e83 |
78| ?? | 00fd | 017a | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.3: Mapping of T.61 Acute Accent Combinations
B.4. Combinations for xc3: (Circumflex)
T.61 has predefined characters for combinations with A, E, I, O, U, Y,
C, G, H, J, S, and W. Unicode also defines the combination for Z.
All of these combinations are present in Table B.4.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c2 | ?? | 0108 | ?? | 00ca | ?? | 011c |
48| 0124 | 00ce | 0134 | ?? | ?? | ?? | ?? | 00d4 |
50| ?? | ?? | ?? | 015c | ?? | 00db | ?? | 0174 |
58| ?? | 0176 | 1e90 | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e2 | ?? | 0109 | ?? | 00ea | ?? | 011d |
68| 0125 | 00ee | 0135 | ?? | ?? | ?? | ?? | 00f4 |
70| ?? | ?? | ?? | 015d | ?? | 00fb | ?? | 0175 |
78| ?? | 0177 | 1e91 | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
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Table B.4: Mapping of T.61 Circumflex Accent Combinations
B.5. Combinations for xc4: (Tilde)
T.61 has predefined characters for combinations with A, I, O, U, and
N. Unicode also defines E, V, and Y. All of these combinations are
present in Table B.5.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c3 | ?? | ?? | ?? | 1ebc | ?? | ?? |
48| ?? | 0128 | ?? | ?? | ?? | ?? | 00d1 | 00d5 |
50| ?? | ?? | ?? | ?? | ?? | 0168 | 1e7c | ?? |
58| ?? | 1ef8 | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e3 | ?? | ?? | ?? | 1ebd | ?? | ?? |
68| ?? | 0129 | ?? | ?? | ?? | ?? | 00f1 | 00f5 |
70| ?? | ?? | ?? | ?? | ?? | 0169 | 1e7d | ?? |
78| ?? | 1ef9 | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.5: Mapping of T.61 Tilde Accent Combinations
B.6. Combinations for xc5: (Macron)
T.61 has predefined characters for combinations with A, E, I, O, and
U. Unicode also defines Y, G, and AE. All of these combinations are
present in Table B.6.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 0100 | ?? | ?? | ?? | 0112 | ?? | 1e20 |
48| ?? | 012a | ?? | ?? | ?? | ?? | ?? | 014c |
50| ?? | ?? | ?? | ?? | ?? | 016a | ?? | ?? |
58| ?? | 0232 | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 0101 | ?? | ?? | ?? | 0113 | ?? | 1e21 |
68| ?? | 012b | ?? | ?? | ?? | ?? | ?? | 014d |
70| ?? | ?? | ?? | ?? | ?? | 016b | ?? | ?? |
78| ?? | 0233 | ?? | ?? | ?? | ?? | ?? | ?? |
e0| ?? | 01e2 | ?? | ?? | ?? | ?? | ?? | ?? |
f0| ?? | 01e3 | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.6: Mapping of T.61 Macron Accent Combinations
B.7. Combinations for xc6: (Breve)
T.61 has predefined characters for combinations with A, U, and G.
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Unicode also defines E, I, and O. All of these combinations are
present in Table B.7.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 0102 | ?? | ?? | ?? | 0114 | ?? | 011e |
48| ?? | 012c | ?? | ?? | ?? | ?? | ?? | 014e |
50| ?? | ?? | ?? | ?? | ?? | 016c | ?? | ?? |
58| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 0103 | ?? | ?? | ?? | 0115 | ?? | 011f |
68| ?? | 012d | ?? | ?? | ?? | ?? | 00f1 | 014f |
70| ?? | ?? | ?? | ?? | ?? | 016d | ?? | ?? |
78| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.7: Mapping of T.61 Breve Accent Combinations
B.8. Combinations for xc7: (Dot Above)
T.61 has predefined characters for C, E, G, I, and Z. Unicode also
defines A, O, B, D, F, H, M, N, P, R, S, T, W, X, and Y. All of these
combinations are present in Table B.8.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 0226 | 1e02 | 010a | 1e0a | 0116 | 1e1e | 0120 |
48| 1e22 | 0130 | ?? | ?? | ?? | 1e40 | 1e44 | 022e |
50| 1e56 | ?? | 1e58 | 1e60 | 1e6a | ?? | ?? | 1e86 |
58| 1e8a | 1e8e | 017b | ?? | ?? | ?? | ?? | ?? |
60| ?? | 0227 | 1e03 | 010b | 1e0b | 0117 | 1e1f | 0121 |
68| 1e23 | ?? | ?? | ?? | ?? | 1e41 | 1e45 | 022f |
70| 1e57 | ?? | 1e59 | 1e61 | 1e6b | ?? | ?? | 1e87 |
78| 1e8b | 1e8f | 017c | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.8: Mapping of T.61 Dot Above Accent Combinations
B.9. Combinations for xc8: (Diaeresis)
T.61 has predefined characters for A, E, I, O, U, and Y. Unicode also
defines H, W, X, and t. All of these combinations are present in
Table B.9.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c4 | ?? | ?? | ?? | 00cb | ?? | ?? |
48| 1e26 | 00cf | ?? | ?? | ?? | ?? | ?? | 00d6 |
50| ?? | ?? | ?? | ?? | ?? | 00dc | ?? | 1e84 |
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58| 1e8c | 0178 | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e4 | ?? | ?? | ?? | 00eb | ?? | ?? |
68| 1e27 | 00ef | ?? | ?? | ?? | ?? | ?? | 00f6 |
70| ?? | ?? | ?? | ?? | 1e97 | 00fc | ?? | 1e85 |
78| 1e8d | 00ff | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.8: Mapping of T.61 Diaeresis Accent Combinations
B.10. Combinations for xca: (Ring Above)
T.61 has predefined characters for A, and U. Unicode also defines w
and y. All of these combinations are present in Table B.10.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 00c5 | ?? | ?? | ?? | ?? | ?? | ?? |
48| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
50| ?? | ?? | ?? | ?? | ?? | 016e | ?? | ?? |
58| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 00e5 | ?? | ?? | ?? | ?? | ?? | ?? |
68| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
70| ?? | ?? | ?? | ?? | ?? | 016f | ?? | 1e98 |
78| ?? | 1e99 | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.10: Mapping of T.61 Ring Above Accent Combinations
B.11. Combinations for xcb: (Cedilla)
T.61 has predefined characters for C, G, K, L, N, R, S, and T.
Unicode also defines E, D, and H. All of these combinations are
present in Table B.11.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | ?? | ?? | 00c7 | 1e10 | 0228 | ?? | 0122 |
48| 1e28 | ?? | ?? | 0136 | 013b | ?? | 0145 | ?? |
50| ?? | ?? | 0156 | 015e | 0162 | ?? | ?? | ?? |
58| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | ?? | ?? | 00e7 | 1e11 | 0229 | ?? | 0123 |
68| 1e29 | ?? | ?? | 0137 | 013c | ?? | 0146 | ?? |
70| ?? | ?? | 0157 | 015f | 0163 | ?? | ?? | ?? |
78| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.11: Mapping of T.61 Cedilla Accent Combinations
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B.12. Combinations for xcd: (Double Acute Accent)
T.61 has predefined characters for O, and U. These combinations are
present in Table B.12.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
48| ?? | ?? | ?? | ?? | ?? | ?? | ?? | 0150 |
50| ?? | ?? | ?? | ?? | ?? | 0170 | ?? | ?? |
68| ?? | ?? | ?? | ?? | ?? | ?? | ?? | 0151 |
70| ?? | ?? | ?? | ?? | ?? | 0171 | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.12: Mapping of T.61 Double Acute Accent Combinations
B.13. Combinations for xce: (Ogonek)
T.61 has predefined characters for A, E, I, and U. Unicode also
defines the combination for O. All of these combinations are present
in Table B.13.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 0104 | ?? | ?? | ?? | 0118 | ?? | ?? |
48| ?? | 012e | ?? | ?? | ?? | ?? | ?? | 01ea |
50| ?? | ?? | ?? | ?? | ?? | 0172 | ?? | ?? |
58| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
60| ?? | 0105 | ?? | ?? | ?? | 0119 | ?? | ?? |
68| ?? | 012f | ?? | ?? | ?? | ?? | ?? | 01eb |
70| ?? | ?? | ?? | ?? | ?? | 0173 | ?? | ?? |
78| ?? | ?? | ?? | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.13: Mapping of T.61 Ogonek Accent Combinations
B.14. Combinations for xcf: (Caron)
T.61 has predefined characters for C, D, E, L, N, R, S, T, and Z.
Unicode also defines A, I, O, U, G, H, j,and K. All of these
combinations are present in Table B.14.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
--+------+------+------+------+------+------+------+------+
40| ?? | 01cd | ?? | 010c | 010e | 011a | ?? | 01e6 |
48| 021e | 01cf | ?? | 01e8 | 013d | ?? | 0147 | 01d1 |
50| ?? | ?? | 0158 | 0160 | 0164 | 01d3 | ?? | ?? |
58| ?? | ?? | 017d | ?? | ?? | ?? | ?? | ?? |
60| ?? | 01ce | ?? | 010d | 010f | 011b | ?? | 01e7 |
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68| 021f | 01d0 | 01f0 | 01e9 | 013e | ?? | 0148 | 01d2 |
70| ?? | ?? | 0159 | 0161 | 0165 | 01d4 | ?? | ?? |
78| ?? | ?? | 017e | ?? | ?? | ?? | ?? | ?? |
--+------+------+------+------+------+------+------+------+
Table B.14: Mapping of T.61 Caron Accent Combinations
Appendix C. Combining Marks
This appendix is normative.
0300-034F 0360-036F 0483-0486 0488-0489 0591-05A1 05A3-05B9 05BB-05BC
05BF 05C1-05C2 05C4 064B-0655 0670 06D6-06DC 06DE-06E4 06E7-06E8
06EA-06ED 0711 0730-074A 07A6-07B0 0901-0903 093C 093E-094F 0951-0954
0962-0963 0981-0983 09BC 09BE-09C4 09C7-09C8 09CB-09CD 09D7 09E2-09E3
0A02 0A3C 0A3E-0A42 0A47-0A48 0A4B-0A4D 0A70-0A71 0A81-0A83 0ABC
0ABE-0AC5 0AC7-0AC9 0ACB-0ACD 0B01-0B03 0B3C 0B3E-0B43 0B47-0B48
0B4B-0B4D 0B56-0B57 0B82 0BBE-0BC2 0BC6-0BC8 0BCA-0BCD 0BD7 0C01-0C03
0C3E-0C44 0C46-0C48 0C4A-0C4D 0C55-0C56 0C82-0C83 0CBE-0CC4 0CC6-0CC8
0CCA-0CCD 0CD5-0CD6 0D02-0D03 0D3E-0D43 0D46-0D48 0D4A-0D4D 0D57
0D82-0D83 0DCA 0DCF-0DD4 0DD6 0DD8-0DDF 0DF2-0DF3 0E31 0E34-0E3A
0E47-0E4E 0EB1 0EB4-0EB9 0EBB-0EBC 0EC8-0ECD 0F18-0F19 0F35 0F37 0F39
0F3E-0F3F 0F71-0F84 0F86-0F87 0F90-0F97 0F99-0FBC 0FC6 102C-1032
1036-1039 1056-1059 1712-1714 1732-1734 1752-1753 1772-1773 17B4-17D3
180B-180D 18A9 20D0-20EA 302A-302F 3099-309A FB1E FE00-FE0F FE20-FE23
1D165-1D169 1D16D-1D172 1D17B-1D182 1D185-1D18B 1D1AA-1D1AD
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