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- Network Working Group H. Nussbacher
- Request for Comments: 1555 Israeli Inter-University
- Category: Informational Computer Center
- Y. Bourvine
- Hebrew University
- December 1993
-
-
- Hebrew Character Encoding for Internet Messages
-
- Status of this Memo
-
- This memo provides information for the Internet community. This memo
- does not specify an Internet standard of any kind. Distribution of
- this memo is unlimited.
-
- Abstract
-
- This document describes the encoding used in electronic mail [RFC822]
- for transferring Hebrew. The standard devised makes use of MIME
- [RFC1521] and ISO-8859-8.
-
- Description
-
- All Hebrew text when transferred via e-mail must first be translated
- into ISO-8859-8, and then encoded using either Quoted-Printable
- (preferable) or Base64, as defined in MIME.
-
- The following table provides the four most common Hebrew encodings:
-
- PC IBM PC ISO
- Hebrew 8859-8
- letter 8-bit 7-bit 8-bit
- Ascii EBCDIC Ascii Ascii
- ---------- ----- ------ ----- ------
- alef 128 41 96 224
- bet 129 42 97 225
- gimel 130 43 98 226
- dalet 131 44 99 227
- he 132 45 100 228
- vav 133 46 101 229
- zayin 134 47 102 230
- het 135 48 103 231
- tet 136 49 104 232
- yod 137 51 105 233
- kaf sofit 138 52 106 234
- kaf 139 53 107 235
- lamed 140 54 108 236
-
-
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- Nussbacher & Bourvine [Page 1]
-
- RFC 1555 Hebrew Character Encoding December 1993
-
-
- mem sofit 141 55 109 237
- mem 142 56 110 238
- nun sofit 143 57 111 239
- nun 144 58 112 240
- samekh 145 59 113 241
- ayin 146 62 114 242
- pe sofit 147 63 115 243
- pe 148 64 116 244
- tsadi sofit 149 65 117 245
- tsadi 150 66 118 246
- qof 151 67 119 247
- resh 152 68 120 248
- shin 153 69 121 249
- tav 154 71 122 250
-
- Note: All values are in decimal ASCII except for the EBCDIC column
- which is in hexadecimal.
-
- ISO 8859-8 8-bit ASCII is also known as IBM Codepage 862.
-
- The default directionality of the text is visual. This means that
- the Hebrew text is encoded from left to right (even though Hebrew
- text is entered right to left) and is transmitted from left to right
- via the standard MIME mechanisms. Other methods to control
- directionality are supported and are covered in the complementary RFC
- 1556, "Handling of Bi-directional Texts in MIME".
-
- All discussion regarding Hebrew in email, as well as discussions of
- Hebrew in other TCP/IP protocols, is discussed in the ilan-
- h@vm.tau.ac.il list. To subscribe send mail to listserv@vm.tau.ac.il
- with one line of text as follows:
-
- subscribe ilan-h firstname lastname
-
- MIME Considerations
-
- Mail that is sent that contains Hebrew must contain the following
- minimum amount of MIME headers:
-
- MIME-Version: 1.0
- Content-type: text/plain; charset=ISO-8859-8
- Content-transfer-encoding: BASE64 | Quoted-Printable
-
- Users should keep their text to within 72 columns so as to allow
- email quoting via the prefixing of each line with a ">". Users
- should also realize that not all MIME implementations handle email
- quoting properly, so quoting email that contains Hebrew text may lead
- to problems.
-
-
-
- Nussbacher & Bourvine [Page 2]
-
- RFC 1555 Hebrew Character Encoding December 1993
-
-
- In the future, when all email systems implement fully transparent 8-
- bit email as defined in RFC 1425 and RFC 1426 this standard will
- become partially obsolete. The "Content-type:" field will still be
- necessary, as well as directionality (which might be implicit for
- 8BIT, but is something for future discussion), but the "Content-
- transfer-encoding" will be altered to use 8BIT rather than Base64 or
- Quoted-Printable.
-
- Optional
-
- It is recommended, although not required, to support Hebrew encoding
- in mail headers as specified in RFC 1522. Specifically, the Q-
- encoding format is to be the default method used for encoding Hebrew
- in Internet mail headers and not the B-encoding method.
-
- Caveats
-
- Within Israel there are in excess of 40 Listserv lists which will now
- start using Hebrew for part of their conversations. Normally,
- Listserv will deliver mail from a distribution list with a
- "shortened" header, one that does not include the extra MIME headers.
- This will cause the MIME encoding to be left intact and the user
- agent decoding software will not be able to interpret the mail. Each
- user is able to customize how Listserv delivers mail. For lists that
- contain Hebrew, users should send mail to Listserv with the following
- command:
-
- set listname full
-
- where listname is the name of the list which the user wants full,
- unabridged headers to appear. This will update their private entry
- and all subsequent mail from that list will be with full RFC822
- headers, including MIME headers.
-
- In addition, Listserv usually maintains automatic archives of all
- postings to a list. These archives, contained in the file "listname
- LOGyymm", do not contain the MIME headers, so all encoding
- information will be lost. This is a limitation of the Listserv
- software.
-
-
-
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- Nussbacher & Bourvine [Page 3]
-
- RFC 1555 Hebrew Character Encoding December 1993
-
-
- Example
-
- Below is a short example of Quoted-Printable encoded Hebrew email:
-
- Date: Sun, 06 Jun 93 15:25:35 IDT
- From: Hank Nussbacher <HANK@VM.BIU.AC.IL>
- Subject: Sample Hebrew mail
- To: Hank Nussbacher <Hank@BARILVM>,
- Yehavi Bourvine <yehavi@hujivms>
- MIME-Version: 1.0
- Content-Type: Text/plain; charset=ISO-8859-8
- Content-Transfer-Encoding: QUOTED-PRINTABLE
-
- The end of this line contains Hebrew .=EC=E0=F8=F9=E9 =F5=
- =F8=E0=EE =ED=E5=EC=F9
-
-
- Hank Nussbacher =F8=EB=E1=F1=E5=
- =F0 =F7=F0=E4
-
- Acknowledgements
-
- Many thanks to Rafi Sadowsky and Nathaniel Borenstein for all their
- help.
-
- References
-
- [ISO-8859] Information Processing -- 8-bit Single-Byte Coded
- Graphic Character Sets, Part 8: Latin/Hebrew alphabet,
- ISO 8859-8, 1988.
-
- [RFC822] Crocker, D., "Standard for the Format of ARPA Internet
- Text Messages", STD 11, RFC 822, UDEL, August 1982.
-
- [RFC1425] Klensin, J., Freed N., Rose M., Stefferud E., and
- D. Crocker, "SMTP Service Extensions", RFC 1425,
- United Nations University, Innosoft International, Inc.,
- Dover Beach Consulting, Inc., Network Management
- Associates, Inc., The Branch Office, February 1993.
-
- [RFC1426] Klensin, J., Freed N., Rose M., Stefferud E., and
- D. Crocker, "SMTP Service Extension for 8bit-MIME
- Transport", RFC 1426, United Nations University, Innosoft
- International, Inc., Dover Beach Consulting, Inc., Network
- Management Associates, Inc., The Branch Office, February
- 1993.
-
-
-
-
-
- Nussbacher & Bourvine [Page 4]
-
- RFC 1555 Hebrew Character Encoding December 1993
-
-
- [RFC1521] Borenstein N., and N. Freed, "MIME (Multipurpose
- Internet Mail Extensions) Part One: Mechanisms for
- Specifying and Describing the Format of Internet Message
- Bodies", Bellcore, Innosoft, September 1993.
-
- [RFC1522] Moore K., "MIME Part Two: Message Header Extensions for
- Non-ASCII Text", University of Tennessee, September 1993.
-
- Security Considerations
-
- Security issues are not discussed in this memo.
-
- Authors' Addresses
-
- Hank Nussbacher
- Computer Center
- Tel Aviv University
- Ramat Aviv
- Israel
-
- Fax: +972 3 6409118
- Phone: +972 3 6408309
- EMail: hank@vm.tau.ac.il
-
-
- Yehavi Bourvine
- Computer Center
- Hebrew University
- Jerusalem
- Israel
-
- Phone: +972 2 585684
- Fax: +972 2 527349
- EMail: yehavi@vms.huji.ac.il
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- Nussbacher & Bourvine [Page 5]
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