Internet-Draft Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation Expires in six months 26 May 2003 LDAP: Internationalized String Preparation Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Distribution of this memo is unlimited. Technical discussion of this document will take place on the IETF LDAP Revision Working Group mailing list . Please send editorial comments directly to the author . Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' The list of current Internet-Drafts can be accessed at . The list of Internet-Draft Shadow Directories can be accessed at . Copyright (C) The Internet Society (2003). All Rights Reserved. Please see the Full Copyright section near the end of this document for more information. Abstract The previous Lightweight Directory Access Protocol (LDAP) technical specifications did not precisely define how string matching is to be performed. This lead to a number of usability and interoperability problems. This document defines string preparation algorithms for matching rules defined for use in LDAP. Zeilenga LDAPprep [Page 1] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 Conventions 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 or . 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]. 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. 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 characters from the Universal Character Set (UCS) [ISO10646], a superset of Unicode [Unicode]. Zeilenga LDAPprep [Page 2] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 UCS-based 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 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 strings for matching. 1.3. Relationship to "stringprep" The string preparation algorithms described in this document are based upon the "stringprep" approach [RFC3454]. 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" [RFC3454] 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; b) after applying the Unicode string preparation steps outlined in "stringprep", characters insignificant to the matching rules are removed. Hence, preparation of 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 Zeilenga LDAPprep [Page 3] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 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 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 string match rule evaluation. 1) Transcode 2) Map 3) Normalize 4) Prohibit 5) Check bidi 6) Insignificant Character Removal Failure in any step is be cause the assertion to be 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. Zeilenga LDAPprep [Page 4] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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). If the implementation is unable or unwilling to perform the transcoding as described above, or the transcoding fails, this step fails and the assertion is evaluated to Undefined. The transcoded string is the output 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 points (e.g., Cc) or code points with a control function (e.g., Cf) are mapped to nothing. 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 Zp) are mapped to SPACE (U+0020). For case ignore, numeric, and stored prefix string matching rules, characters are case folded per B.2 of [RFC3454]. 2.3. Normalize The input string is be normalized to Unicode Form KC (compatibility composed) as described in [UAX15]. 2.4. Prohibit All Unassigned, Private Use, and non-character code points are prohibited. Surrogate codes (U+D800-DFFFF) are prohibited. The REPLACEMENT CHARACTER (U+FFFD) code point is prohibited. The first code point of a string is prohibited from being a combining Zeilenga LDAPprep [Page 5] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 character. Empty strings are prohibited. The step fails and the assertion is evaluated to Undefined if the input string contains any prohibited code point. The output string is the input string. 2.5. Check bidi There are no bidirectional restrictions. The output string is the input string. 2.5. 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). The following spaces are regarded as not significant and are to be 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). A string consisting entirely of spaces is equivalent to a string containing exactly one space. For example, removal of spaces from the Form KC string: "foobar" Zeilenga LDAPprep [Page 6] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 would result in the output string: "foobar" and the Form KC string: "" would result in the output string: "". 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 and are to be removed. For example, removal of spaces from the Form KC string: "123456" would result in the output string: "123456" and the Form KC string: "" would result in an empty output string. 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 regarded as not significant and are to be removed. 3. Security Considerations "Preparation for International Strings ('stringprep')" [RFC3454] security considerations generally apply to the algorithms described here. 4. Contributors Appendix A and B of this document were authored by Howard Chu of Symas Corporation (based upon information provided Zeilenga LDAPprep [Page 7] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 in RFC 1345). 5. Acknowledgments The approach used in this document is based upon design principles and algorithms described in "Preparation of Internationalized Strings ('stringprep')" [RFC3454] by Paul Hoffman and Marc Blanchet. Some additional guidance was drawn from Unicode Technical Standards, Technical Reports, and Notes. 6. Author's Address Kurt Zeilenga E-mail: 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. [RFC3454] Hoffman, P. and M. Blanchet, "Preparation of Internationalized Strings ('stringprep')", RFC 3454, December 2002. [Roadmap] Zeilenga, K. (editor), "LDAP: Technical Specification Road Map", draft-ietf-ldapbis-roadmap-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. [ISO10646] International Organization for Standardization, "Universal Multiple-Octet Coded Character Set (UCS) - Architecture and Basic Multilingual Plane", ISO/IEC 10646-1 : 1993. [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" (http://www.unicode.org/reports/tr28/). Zeilenga LDAPprep [Page 8] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 [UAX15] Davis, M. and M. Duerst, "Unicode Standard Annex #15: Unicode Normalization Forms, Version 3.2.0". , 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", . [CharModel] Whistler, K. and M. Davis, "Unicode Technical Report #17, Character Encoding Model", UTR17, , 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. Appendix A. Teletex (T.61) to Unicode Zeilenga LDAPprep [Page 9] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 a 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 Probhibit 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 | f0| 0138 | 00e6 | 0111 | 00f0 | 0127 | 0131 | 0133 | 0140 | f8| 0142 | 00f8 | 0153 | 00df | 00fe | 0167 | 014b | ?? | Zeilenga LDAPprep [Page 10] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 --+------+------+------+------+------+------+------+------+ 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. B.1. Combinations with SPACE Accents may be combined with a to generate the accent by itself. For each accent code, the result of combining with 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 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 | ?? | ?? | 48| ?? | 00cc | ?? | ?? | ?? | ?? | 01f8 | 00d2 | 50| ?? | ?? | ?? | ?? | ?? | 00d9 | ?? | 1e80 | Zeilenga LDAPprep [Page 11] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 | ?? | ?? | ?? | ?? | ?? | --+------+------+------+------+------+------+------+------+ Table B.4: Mapping of T.61 Circumflex Accent Combinations Zeilenga LDAPprep [Page 12] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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. Unicode also defines E, I, and O. All of these combinations are present in Table B.7. Zeilenga LDAPprep [Page 13] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 | 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 | 58| 1e8c | 0178 | ?? | ?? | ?? | ?? | ?? | ?? | 60| ?? | 00e4 | ?? | ?? | ?? | 00eb | ?? | ?? | 68| 1e27 | 00ef | ?? | ?? | ?? | ?? | ?? | 00f6 | Zeilenga LDAPprep [Page 14] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 B.12. Combinations for xcd: (Double Acute Accent) T.61 has predefined characters for O, and U. These combinations are Zeilenga LDAPprep [Page 15] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 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 | 68| 021f | 01d0 | 01f0 | 01e9 | 013e | ?? | 0148 | 01d2 | 70| ?? | ?? | 0159 | 0161 | 0165 | 01d4 | ?? | ?? | 78| ?? | ?? | 017e | ?? | ?? | ?? | ?? | ?? | Zeilenga LDAPprep [Page 16] Internet-Draft draft-ietf-ldapbis-strprep-00 26 May 2003 --+------+------+------+------+------+------+------+------+ Table B.14: Mapping of T.61 Caron Accent Combinations Intellectual Property Rights The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. 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