[Mirrored from: http://dns.hti.umich.edu/htistaff/pubs/1997/janete.01/]

Options for Presentation of Multilingual Text:

Use of the Unicode Standard

by Janet C. Erickson
Prepared for John Price-Wilkin as a
Digital Information Associate Research Project
March 14, 1997

In the current model of electronic publishing, texts can be delivered with a cross-application approach using the Standard Generalized Markup Language (SGML). This same level of cross-platform and cross-application delivery has not been achieved for all of the characters that these texts include. An ideal solution to the problems in character representation would be cross-platform, flexible, and durable. Many in the computing, publishing, and library worlds have suggested that the Unicode standard is the wave of the future. The following seeks to demonstrate the frailties of other options that are considered for text presentation and the success of Unicode and its sibling standards in addressing these weaknesses.


Multilingualism has long been a concern in libraries. Most libraries collect and catalog items that are not produced in the local language. Cataloging records for these documents, either cards or OPAC entries, frequently contain letters or characters that are not found on a standard typewriter or computer keyboard. Librarians have applied workarounds or local solutions, though each has its downside. In the past, extended character sets made available through various means have been sufficient to deal with the problems of multilingual and foreign text. However, these character set solutions are often standardized only to a nation, an industry, a profession, or an even smaller group. Competing standards mean that documents written using one character set must be modified for use on systems that use another character set or sets or they cannot be read. Service to a growing international audience is imperative. Digital libraries are springing up and their communities span the globe. The world needs to come to an agreement on how the information that they provide can be understood unambiguously by computer systems of their newfound audience.

The University of Michigan's Humanities Text Initiative currently delivers texts with a cross-application approach using the Standard Generalized Markup Language (SGML) but because of character set limitations cannot yet provide the same level of cross-platform and cross-application delivery for all of the characters that these texts include. An ideal solution to the many problems with character representation would be cross-platform, flexible, reusable, and durable. Many in the computing, publishing, and library worlds have suggested that the Unicode standard is the wave of the future, but does it meet these criteria?

The Unicode standard is intended to provide a 'unique, universal, and uniform' encoding(1) for each character in all living languages (plus a few dead ones). In this report, I intend to investigate whether movement should be made toward embracing the Unicode standard for presentation of materials on the World Wide Web and other worldwide media, what other options are available, and whether the Unicode standard is an effective means for digital libraries and publishers to provide multilingual information.

Any attempt to provide multilingual information over the Web runs into problems beyond the choice of character set. These include alphabetization and sorting, searching, compression and compaction, and the particular problems of presenting Arabic and the CJK languages (Chinese, Japanese, and Korean). These will not be dealt with here in any depth. Each of these is a problem unto itself and deserves an investigation of its own.

Cross-application compatibility is something for which many strive. The Standard Generalized Markup Language (SGML) has promoted this through an international standard (ISO 8879) of unambiguous document content and structure coding. Each facet of a document can be identified and regularized through user- or organization-defined rules. Each character that does not come naturally to the local computer can be coded as an entity, a low-level representation of that character the replacement of which is left to the underlying system, as directed by the user. For each system (Macintosh, IBM PC compatible, NeXT, UNIX, etc.), a different manner for replacing these characters must be made; there is currently little agreement on where these are placed in character sets, the source of this replacement. When the different encodings used by other countries is thrown into the mix, the size of the problem becomes overwhelming. An initial step in resolving these differences is to agree on where each character should be placed and to have a place for every character. While this may sound simple, efforts in this direction have been hampered by the proliferation of the older standards, which have age and localized use on their side. Each system (by computer type and locale) has been developed for the needs of a nation, a language group, or other particular group. Many share the same roots with ASCII, but variations on its theme abound.

Localized variations complicate efforts to transport information among these groups. One set of glyphs that has proven useful to a great many people is from the Greek language. Greek citizens, classical scholars, philosophers, lexicographers, mathematicians, and physicists are just a few of the groups who find need of Greek characters. HTI uses Greek in many ways and in many text collections. We cannot rely upon a common understanding of the location or presence of the Greek characters in any one character set on the computers of our user population. Each audience has found their own way to present Greek. HTI has tried many things to solve the Greek presentation issue -- a combination of methods has proved most useful, but still not every user is served.

The solution to our specific problems will assist more than the HTI's particular audience. It will allow more effective and more efficient communication with the larger global community. Japan and China will seem closer as the need to change operating systems to change language is eliminated. The smooth transitions made possible by the World Wide Web will pale in comparison, as uniform, barrier-free foreign language support becomes a part of every computer system.

There are many ways to approach problems of computers and languages. Solutions range in complexity from transliteration and GIFs that keep all other aspects of the computer the same, to the Unicode standard, which involves more widespread changes. An understanding of many of the solutions requires more knowledge of how characters work on computers.

How Characters on Computers Work

Computers store information in groups of bits that are either 0 or 1, off or on. Bits are usually stored in groups of eight to form a byte. Since each bit has two possible values, the number of available combinations of 1s and 0s is 28 (256) for 8-bit bytes. In 7-bit codes, the most significant bit is always 0, with the remaining seven bits of the byte combining 1s and 0s to make 27 or 128 combinations. Computers have traditionally stored characters in single bytes. The 128 and 256 correspond to the number of values that a computer can use for characters, based on how much space is allocated for each.(2) A character set, also known as a coded character set or code page, is "a set of characters, each associated with a unique pattern of bits, for use in representing character data on an electronic digital binary computer."(3)

The terminology used in reference to characters and character sets often causes difficulties in communicating about them. First, standards organizations use their own terms for many of the same ideas. Hence, we get 'character set,' 'coded character set,' and 'code page' all meaning the same thing. To minimize problems with variant language, a glossary has been included as a supplement to this paper. The distinction between fonts and character sets is addressed below in "Font-related solutions." Some of the more essential terms, bits and bytes, are familiar to many computer users, thought the accepted measure of eight bits in a byte is imprecise. A byte is formally defined as "a bit pattern of fixed length."(4) In the late 1950s, it was estimated that 75 percent of the data processed by computers was numeric data, which could be represented with only four bits. Seven bits was determined to be necessary for the remaining graphic and control characters (letters/symbols and carriage return etc.) for communication devices. Thus was born what would become ASCII, a 7-bit character set.(5) In many applications, modern computers use 8-bit bytes. What most of use on our computers these days is one of a variety of 8-bit extended character sets based on ASCII.

Another area of confusion regards characters and glyphs. There is a difference between a character and a glyph -- a character is the more abstract ideal of a letter, symbol, or number, while glyphs are the representations of these that appears on-screen and on the printed page. An example of the difference between these is the character 'a' which can appear as the glyphs 'a' oralternate 'a' glyph. While this distinction may not mean much in American English, the Arabic language, for example, uses different glyphs of the same character when it appears in different parts of a word.(6)

A Short History of Character Sets

The ASCII (American Standard Code for Information Interchange) character set is a 7-bit scheme, with the first, all-zero code reserved as a null code, leaving 127 values for characters. It is the character set that is probably the most familiar to users as its characters appear on computer keyboards. ASCII is based on the international standard ISO 646, first published as ANSI X3.4 in 1968, which is also the basis for similar character sets in other countries. In 1991, the International Organization for Standardization (ISO) published a character set that has all of the same graphic characters as US-ASCII, calling it ISO 646-IRV:1991 (International Reference Version).(7)

IBM created the Extended Binary Coded Decimal Interchange Code (more commonly known as EBCDIC), an 8-bit character set, in the 1960s. This is an industry standard, rather than a national or international one.(8) IBM is said to have an internal register of more than a thousand versions of EBCDIC(9) as it has been modified to fit the particular needs of the user population. Use of EBCDIC has declined since its heyday in the 1960s, though mainframe computers using this character set continue to be serve important functions in organizations.

The needs of the world have gone beyond the capabilities of the basic ASCII and EBCDIC character sets. Other character sets will be introduced below, as that additional layer of complexity is identified. The first two possible solutions to the problem of multilingual computing, transliteration and character images, do not require more than the 128 characters of ASCII.


Transliteration is the spelling or representing of characters and words in one alphabet by using another alphabet. Phonological transliteration is a common solution for foreign titles and author fields in library catalog records. This type of transliteration needs to result in words and characters that are readable. Because of this, simply assigning ASCII characters to them in some pattern is insufficient, even if that pattern is regular and otherwise informative. For example, the Chinese characters for the numbers one, two, and three can be transliterated as YI_1_4E00, ER_4_4E8C, and SAN_1_4E09, with the parts corresponding to syllable, tone, and Unicode code value.(10) For systems that cannot present the necessary glyphs for nonlocal languages, transliteration is the only way for such information to be presented. For many languages, the transfer from the original alphabet to another is unambiguous. Fidelity is not ensured, however, and native speakers of the language are not properly served by these romanized words.

For non-alphabetic languages, such as Chinese, there are many more ideographic characters than can be unambiguously represented with the ASCII character set. Much ambiguity is introduced through transliteration of these languages. Subtle distinctions in Chinese script are lost in romanization in regard to its many homophones. In addition, not all countries or groups follow the same transliteration scheme. Some schemes have proven to be difficult or impossible to transliterate back to the original language or are unintelligible in their romanized form, especially to a native speaker. In a library context, many online catalogs ignore diacritical distinctions as unimportant. Thus, a search on one transliterated term that varies from another only in its diacritics would produce many false drops. In all, transliteration of both alphabetic and ideographic languages is not a sufficient solution to the world's communication blockage.

Character Images

A second solution involves the use of GIF, PNG, or other images to display the characters that are not available in the local character set. This has worked well for presentation of the relatively small portions of Greek in the Humanities Text Initiative's version of the English Poetry Database (Chadwyck-Healey, Ltd.) where the user is not likely to search for that particular piece of text. The HTML code is automatically generated from the original SGML, with a mapping file taking care of what image to show for each desired character. The sections of Greek in the EPD are typically isolated lines of poetry, so that positioning of these images within the line of English text and matching the font are unnecessary. As can be seen in other attempted applications of this solution, the placement of a single Middle English character, yogh, within the lines of text, sizing and spacing of images is of utmost importance for the basic aesthetics of the text. The current instantiations of Web and SGML browsers are unable to position the images within lines of text to the degree necessary for invisible incorporation of character images.

On first glance, images seem the ideal -- most if not all browsers understand their content and they are fairly simple to produce. However, these images are not searchable, and what is seen on the screen is what is copied to a local drive in saving the file. A person saving an image-filled page receives only a reference to the image, not the image itself. Other options would need to be provided for saving the file in a format that would include these characters as something comprehensible to the user's local system. This leads us back to the question of what format and encoding this saved file should have. Therefore, while the problems of display may be solved thus, images in and of themselves do not provide a satisfactory resolution.

Beyond 128 Characters

It may be evident that the 7-bit ASCII standard severely limits the repertoire of characters available for library bibliographic needs and other multilingual applications. Three methods have often been used to gain additional characters: substitution, 8-bit character sets, and escape sequences. Substitution is the replacement of the 12 allowed characters in ISO 646 IRV:1991 with locally applicable characters.(11) We have already seen an 8-bit character set in EBCDIC. ASCII has been modified to utilize that eighth bit and called extended ASCII by programmers to distinguish it from the 7-bit form. ISO 646's 7-bit coding was extended in this manner in the ISO/IEC 8859 standard, the first portion of which is called Latin-1. Latin-1 served as the basis for the character set used in Microsoft Windows.(12) Figure 1, below, shows some of the many versions of extended ASCII for use in Windows.

Figure 1
Windows 8-bit Character Sets

Code Page 1250 1251 1252 1253 1254 1255 etc.
Upper 128 Eastern Europe Cyrillic West European Greek Turkish Hebrew etc.

Even the 256 characters available to an 8-bit character set are insufficient for some uses. Additional character sets are available through shifting and escape codes. An escape code (usually ASCII hexadecimal 1B) announces that another character set, identified in the next bytes, will be used from this point until an end code is found. ISO 2022 defines the use of these escape codes; the European Computer Manufacturers' Association (ECMA) maintains a registry of the character sets accessible in this manner.

The ISO creates international standards, ASCII is a national standard, and EBCDIC is an industry standard. The library world has utilized another type of standard: a professional standard. Professional standards are developed by and for specific groups, such as the Library of Congress and RLIN, rather than for national or international standardization purposes.(14) The USMARC character set (formerly the ALA character set) was developed by the Library of Congress, first published in 1969, and adopted as a U.S. standard in 1985 (ANSI Z39.47-1985). USMARC is an 8-bit character set, though it is also usable as a 7-bit set. It is a variable-byte character set, meaning that non-spacing diacritics such as acute and grave that go over other letters are transmitted as an additional byte before the byte containing the character they modify. Due to the complex character needs in the bibliographic environment, more than one diacritic can be combined with a letter in USMARC. The USMARC character set was adopted by many countries and library systems and modified for their uses, leading to UKMARC (United Kingdom), DANMARC (Denmark), NORMARC (Norway), CANMARC (Canada), IBERMARC (Spain), ANNAMARC (Italy), MARCAL (Latin America), AUSMARC (Australia), JAPAN MARC (Japan), SAMARC (South Africa), SWEMARC (Sweden), and INTERMARC (France and other European countries).(15) MARBI or Machine-Readable Bibliographic Information oversees the USMARC character set and other standards for libraries. It is an interdivisional committee with representatives from LITA, RASD, and ALCST.(16)

An international effort at providing character sets that are useful for multilingual needs resulted in the ISO 8859 series. These nine character sets, 8859-1 to 8859-10 (8859-4 was withdrawn for revision),(17) cover Western European, Central and Eastern European, Arabic, and Greek languages. ISO 8859-1, the extension to ISO 646 more commonly known as Latin-1, is sufficient to deal with Western European languages and is the current official limit on the characters available to the Hypertext Markup Language (HTML).

Double-byte character sets, or DBCS, encode certain characters using a single octet and some using two octets. A major problem with this was that each character has to be tested to see if it is 8 or 16 bits long. Since the encoding string is interpreted in 8-bit chunks, no single octet may have the same pattern as a control character (escape, nul, etc.), even if another interpretion is clearly indicated by the previous octet. This means that DBCS' can be transmitted with few mis-interpretations. Character sets for Far Eastern languages have typically used DBCS to accommodate their larger character repertoire. In its canonical form, the Unicode standard utilizes 16 bits; unlike DBCS, it includes no 8-bit characters. ISO 10646, in its canonical form called UCS-4, takes up 32 bits for each character. These character sets will be discussed in depth below.

Font-Related Solutions: fonts and character sets

Before moving on to font-related solutions, a distinction needs to be drawn between fonts and character sets. Fonts and character sets are not the same thing. Fonts contain glyphs, not characters (see above and glossary). The code positions of the glyphs are not important, as are the positions of characters in a character set. A Times font may have the same general style whether it's on a Macintosh or IBM-compatible computer, but the code positions of the underlying characters on these systems are significantly different. This difference is invisible for the first 128 characters, as both the Macintosh and Windows character sets incorporate the ASCII character set.

Of the 128 remaining positions in an 8-bit character set, only 11 are in the same position in basic Macintosh and Windows fonts.(18) When a transformation format such as Microsoft's Rich Text Format is selected in saving a word processed document, many of the character set differences are dealt with by the underlying system. This is not currently true in the Internet environment. HTML-encoded documents may be created on any computer system and read by any other. It is in this cross-platform environment that differences between the basic character sets of computers show through. The following table shows the areas of commonality between the Windows and Macintosh character sets and selected positions where they differ.

Many companies produce fonts for Windows and for Macintosh with nonroman characters placed in the positions usually reserved for roman characters. In these fonts, what appears when you type an 'a' might be a Greek alpha or Cyrillic R. This circumvents the need to use escape codes to switch character set encodings for nonroman texts. With these fonts in hand, it is a simple task to write a multilingual word-processed document -- simply change the local font when you want other glyphs. The initial problem with this is that you cannot use it on another computer of the same type unless it has the same nonroman fonts installed and available.

Unfortunately, not all fonts follow the same character set; the character you intend to include may appear in a different position in another same-language font so that an incorrect glyph would be displayed if you substituted fonts. For example, scholars use many varieties of Greek fonts, such as SGreek and Attika. Attika's encoding is the same in both its Macintosh and Windows versions (character at decimal position 145 produces the same glyph on each system). While this is a step in the right direction, this cross-platform uniformity is the exception rather than the rule. This cross-platform ability also requires the procurement of a particular commercial add-on. While the price of an add-on may be insignificant compared to the benefits it brings, those without access to the product will not be served. For this reason, a standard, non-proprietary solution is preferable.

As mentioned above, cross-platform character set incompatibilities show up when using Netscape or other Web browser. In general, browsers allow the use of two fonts in display of an HTML document: a proportional font for general text and a fixed font for editable fields and preformatted paragraphs. One or both of these can be changed to a nonroman font, giving access to two fonts in a document. Again, a font based on the same character set needs to be used on each end; otherwise, the correct language may show up but with the wrong glyph. This is due to the fact that most HTML content does not identify the encoding used in creating the document, nor do most HTTP servers transmit this information when it is available. As a result, browsers need to either guess at the encoding used or use a default value. Even if the encoding is specified and transmitted, browsers are limited in what they can do to present the document correctly. Encoding translation tables and suitable font resources are both necessary for proper interpretation and display of documents.(19)

There is also the limitation to two fonts, making presentation of material in multiple languages difficult through this means. Microsoft's browser, Internet Explorer, and Netscape Navigator 3.0 have addressed the fonts issue by adding the face attribute to the font tag in HTML (<font face=Attika>). There is still the expectation that the end user will have the fonts specified in this tag present on their computer.

Another reason that switching fonts to get new characters is an inadequate way to bring multilingual capabilities to life is that it solves only the display portion of the problem. When the text is viewed in another font, it appears as gibberish. For example, the following three sentences were typed using the same keystrokes, but the results are vary significantly:

There is no distinction made between a glyph in position 156 in a Greek font and a glyph in the same position in a Cyrillic font. Changing the fonts used in a document allows display of an almost unlimited array of glyphs, but these glyphs cannot be searched, result in nonsense if switched to another font, are highly system-dependent, and are not present on every computer.

Character Set Switching

Unambiguous communication of text is much simpler when some recognized standard is followed within a document. Mapping tables can be used to convert from one character set to another, assuming no changes have been made to the source character set locally. This is especially useful in an international environment, such as the Web, where no assumption can be made that others are using the same character set that you are.

There are many ways to switch character sets. Users can utilize the local character set and have all incoming documents changed to it by a mediating server. This limits the characters that can be understood locally to those available in the local character set. Another option is to have all computers understand all local character sets. This requires an enormous amount of upkeep, as character set standards are added, changed, or deleted.

There are many character sets that include characters for presentation of the Greek language. ISO 8859-7 covers modern Greek and English. 8859-7 includes all of the basic Greek characters, alpha through omega, plus the diacritics diereses, tonos, and a combined diereses/tonos character. This character set was developed by ISO/TC97/SC2, Character Sets and Information Coding, and adopted by ELOT as a Greek national standard, ELOT 928. Classical or polytonic Greek cannot be produced with only these diacritics. In contrast, ISO 5428 is designed for bibliographic use. It does not match the Greek national standard, but it does include the diacritics necessary for Classical Greek: acute, grave, rough, smooth, circumflex, and diereses. The 1980 version of ISO 5428 also differs from the 1976 version that was used as the basis for INTERMARC's Greek portions.(20)

There has been a proliferation of code pages, so a document may indicate a switch to a code page that is unavailable to or not present on one's computer. While the ECMA registers character sets that can be accessed through methods defined in ISO 2022, this process of registration slows the implementation of them in various contexts. For example, the Research Libraries Group implemented Arabic, Hebrew, and East Asian character sets that are considered privately defined and not registered with ECMA so that the RLG could use these sets.(21) Standardization and registration of these sets is desirable for the additional certainty of support that such registry implies. From here, we can imagine moving from standard, registered code pages to a single character set that includes all of the characters that had been contained in each of the separate character sets.


The best of the previous character sets solutions presented many obstacles to library and publishing efforts toward multilingual computing. Software engineers make up another affected group. International software development was impaired by many things, including stateful encoding, variable-length encoding, and overloaded font systems.(22) Stateful encoding is a problem with shifting character sets, as the character represented by a particular value depends on knowing another value that was indicated earlier in the text stream. This is much like DBCSs (double byte character sets), which contain characters represented by either one or two bytes so each character has to be examined to determine where it ends. Another problem is that character sets have tended to include glyph variants, such as ligatures, that are more presentation forms than different characters. This means that fonts are asked to do more work than they are able to do, keeping track of multiple versions of a character to use in different contexts. In addition, specific language fonts have been used to enable the display of more characters than are available through a single character set.

In response to these problems, Joseph Becker of Xerox PARC, along with Lee Collins and Mark Davis of Apple Computer, began work on a new character encoding. Becker named it "Unicode" for its aim to be three things: universal, covering all modern written languages; unique, with no duplication of characters even if they appear in more than one language; and uniform, with each character being the same length in bits. The Unicode Consortium was incorporated in 1991 as Unicode, Inc., with members Research Libraries Group, Metaphor Computer Systems, Microsoft, IBM, Sun Microsystems, DEC, Adobe, Claris, NeXT, Pacific Rim Connections, Aldus, Go Corp., Lotus, WordPerfect, and Novell. Unicode is defined as "a world-wide character encoding standard based on a 16-bit unit of encoding developed by Unicode, Inc."(23)

Unicode did not evolve on its own. In 1983, the ISO began work on the ISO 10646 character standard, or Universal Multiple-Octet Coded Character Set (UCS) 4 (for the four octets that make up each character's value). ISO 10646, so named to remind us of ASCII's ISO 646, was initially designed with 16-bit characters. The need to retain control codes from other character sets and opposition from Japan and Korea to unification of the Chinese/Japanese/Korean character set meant that 32 bits were needed to hold everything. The standard was criticized for its size, though many schemes of sending only the pertinent bits were suggested to make it workable.(24)

The first edition of the Unicode standard was near completion in 1991 when, at the urging of many in the computer industry, developers of Unicode and ISO 10646 met to join their efforts. Their combined standard was accepted as an international character code standard in spring 1992.(25)Unicode, Inc. published the first volume of the Unicode Standard Version 1.0 in October 1991, and the second volume in June 1992.(26) Unicode is now a 16-bit form of the larger 10646 32-bit standard. The 32-bit pattern is interpreted as four octets: the group octet, plane octet, row octet, and cell octet. The combination of these indicates a unique character.(27) Unicode occupies the Basic Multilingual Plane of 10646, as shown in Figure 2, below.(28)

Figure 2
Map of the Basic Multilingual Plane

The Unicode standard includes tables of cell octet values and the characters represented by these values. An example chart is shown below in Figure 3.

Figure 3
Unicode Block Chart (0000 to 00FF)

Control ASCII Control Latin-1
000 001 002 003 004 005 006 007 008 009 00A 00B 00C 00D 00E 00F
1 SOH DC1 ! 1 A Q a q CTRL CTRL ¡ ± Á Ñ á ñ
2 STX DC2 " 2 B R b r CTRL CTRL ¢ ² Â Ò â ò
3 ETX DC3 # 3 C S c s CTRL CTRL £ ³ Ã Ó ã ó
4 EOT DC4 $ 4 D T d t CTRL CTRL ¤ ´ Ä Ô ä ô
5 ENG NAK % 5 E U e u CTRL CTRL ¥ µ Å Õ å õ
6 ACK SYN & 6 F V f v CTRL CTRL | Æ Ö æ ö
7 BEL ETB ' 7 G W g w CTRL CTRL § Ç × ç ÷
8 BS CAN ( 8 H X h x CTRL CTRL ¨ ¸ È Ø è ø
9 HT EN ) 9 I Y i y CTRL CTRL © ¹ É Ù é ù
A LF SUB * : J Z j z CTRL CTRL ª º Ê Ú ê ú
B VT ESC + ; K [ k { CTRL CTRL « » Ë Û ë û
C FF FS , < L \ l | CTRL CTRL ¬ ¼ Ì Ü ì ü
D CR GS - 0 M ] m } CTRL CTRL - ½ Í Ý í ý
E SG RS . > N ^ n ~ CTRL CTRL ® ¾ Î Þ î þ
F SI US / ? O _ o DEL CTRL CTRL ¿ Ï ß ï ÿ

In its canonical form, Unicode is a 16-bit standard that encompasses 65,536 character spaces (216or 16 bits, each with two possible values, 0 or 1). Over 70 percent of the character spaces have been allocated thus far.(29) The first 256 code positions are identical to ISO Latin-1, which includes the 128 characters of ASCII. These are within the 8,192 spaces for standard alphabetics and phonetics, followed by 4,096 spaces for punctuation, mathematical operators, technical symbols, shapes, patterns, and dingbats. The next section of 4,096 spaces is for CJK symbols, Hangul, and Han compatibility, followed by the largest allocation of more than 20,000 spaces reserved for CJK ideographs. The last area includes a private use area and compatibility characters.(30) Languages covered include all modern languages used for communication, as well as historic forms of languages such as Greek, Hebrew, Latin, Pali, and Sanskrit.

Principles of the Unicode Standard

The fundamental goal of Unicode is to create a unique, uniform, and universal set of characters. In the original design, each character would occupy 16 bits, no more and no less, so that there would be no need to keep track of signature octets early in the text stream that would affect the computer's interpretation of a later character. While there are many precomposed characters included in Unicode for compatibility with existing standards, non-spacing marks can be used with any other character. A 'q-umlaut' could be created if desired. This is especially useful in transliteration or in recording languages that do not have a written component. Unicode provides codes for characters, not glyphs or glyph variations, and no duplication of characters is allowed across languages. Characters from historic character sets have been included. Sorting is left to the application level. Codes are, however, set aside for indication of direction in bidirectional text, often shortened to BIDI.

The characters that make up Unicode came from many sources. It includes all of the unique characters of all major international standards published before 1991, primarily the ISO 6937,(31)8859, and 8879 (SGML) standards. Characters from these standards were not included where they were determined to be glyphs or variants of other characters. Unicode also incorporated characters from the library standards USMARC Latin character set and East Asian Character Code, as well as important national standards.

The library world is responding to the changes made possible by Unicode. MARBI has produced mapping tables from many of its character sets to Unicode. In this process, MARBI encountered several problems. First, seven characters in USMARC did not map cleanly to Unicode; MARBI resolved these. In addition, they encountered problems with so-called "ASCII clones" or characters that appeared in both ASCII and either the Cyrillic, Hebrew, or Arabic character sets of USMARC. This causes problems in round-trip mapping, such that an ASCII clone could be changed to Unicode, but that Unicode character could not be transferred back to its original place in USMARC. It is a many-to-one relationship that MARBI has not reconciled. This is a serious problem, as many historic character sets contain what are considered glyph variants or otherwise the same character in Unicode. These multiple characters can be mapped to the single Unicode character, but there is no indication in Unicode of where they came from and the characters cannot be returned to the exact position from which they originated in the mapping process.(32)

ISO 10646 Formats

Unicode/UCS-2 fits nicely into the larger standard, ISO 10646/UCS-4. The following table illustrates the nesting levels of the various standards incorporated into ISO 10646.

Table 2
Binary Values of Uppercase A

Bits Standard Binary Hex Dec Char
7 ASCII 1000001 41 65 A
8 ISO 8859-1 (Latin-1) 01000001 41 65 A
16 Unicode (10646 UCS-2) (10646 BMP) 00000000 01000001 41 65 A
32 10646 UCS-4 00000000 00000000 00000000 01000001 41 65 A

This table shows how ASCII can be fit into ISO Latin-1 by adding an initial zero. In the same way, Latin-1 with an initial octet of zeros fits into Unicode and Unicode with two initial octets of zeros fits into 10646. With the unification of Unicode and ISO 10646, the question arises of how to transmit data in either format. Sending all four octets of UCS often is not feasible and not all applications can utilize even the 16 bits of Unicode. Several schemes have been developed for these situations: UTF-7, UTF-8, and UTF-16, to accompany the canonical UCS-2 (Unicode) and UCS-4 (10646). The UTF in each of these stands for UCS Transformation Format, followed by the number of bits of transparency required by the transmission channel.(34)

UTF-7 is a mail-safe transformation format of Unicode.(35) It allows transmission of Unicode text through mail and news systems in which characters beyond 7-bit ASCII would be interpreted incorrectly. Characters from 128 and above (decimal values) are accessed through shift sequences; UTF-7 also contains provisions for systems using EBCDIC, which cannot handle all of ASCII's characters.

The 8-bit UTF-8 supplanted the earlier UTF-1 (one octet), also called File System Safe UTF.(36)Characters in UTF-8 are represented by a series of 1, 2, 3, 4, 5, and 6 octets; the number of octets needed for a character is indicated by the number of 1s in the initial octet. UTF-8 can be converted to UCS-4 efficiently, but cannot be directed transformed to UTF-16 (Extended Unicode, see below). UTF-8 is designed so that null bytes and the ASCII slash (/) are protected so that systems for which these characters have additional meaning will not misinterpret their use.

UTF-16 has also been referred to as Extended UCS-2, an extension of Unicode. It allows access to characters outside the Basic Multilingual Plane (BMP) of UCS-4 (ISO 10646) in a UCS-2 encoded string.(37) UTF-16 reserves 1024 codes from the BMP for the high-half zone code and 1024 from the BMP for the low-half zone code. When these codes are combined, they add 917,504 code positions for new characters and 131,072 additional spaces for private use. In this scheme, some characters are represented by one 16-bit UCS-2 code value and some by two 16-bit UCS-2 code values, making this in essence a variable length encoding much like the double-byte character sets (DBCS) mentioned earlier. As in a DBCS, each character in a string has to be examined to determine whether it will be followed by the second half of the character or by a different character. This adds overhead to processing of the character data. It also violates the design goal of Unicode that Unicode will use only one 16-bit code for each character. An alternative is the remapping of non-BMP ISO 10646 characters to the private use area when a file using these characters is imported. This limits the number of non-BMP characters to the size of the private use area (6,400 character spaces). As the non-BMP characters have yet to be assigned, it is unknown if this is a serious hindrance to use of UCS-4.

These transformation formats are important for many reasons. They can be used to send all of the characters of 10646 or Unicode in forms that are not likely to be misinterpreted by historic systems. Byte-order problems, the order in which the multiple octets of Unicode are sent, are avoided in the UTF-8 and UTF-7.(38) Most importantly, UTF-8 in particular is being adopted in the computing community. UTF-8 can be used to represent Unicode and its superset ISO/IEC 10646. Because the characters of the BMP in 10646 are Unicode characters with two all-zero octets added on the front, UTF-8 can be said to convert cleanly to Unicode as well. Characters used in UTF-8 outside the BMP are not available in canonical Unicode -- UTF-16 adds this capability. The compatibility of UTF-8, which is used in Microsoft Office 97, and 16-bit Unicode used in NT, provides access points between these operating systems.

Implementation of the Unicode Standard

Unicode/10646 and the UTFs have been hailed by many in the computing and library communities as an ideal solution to the problems of multiplatform internationalization. "Unicode is the worldwide character-encoding standard destined to replace ASCII and the multitude of other single- and multibyte character sets currently in existence."(39) "Unicode makes so much sense, it seems inevitable."(40) "Once multiscript universal systems are widely available....at long last, cataloging rules and machine-readable cataloging will be in harmony."(41) Despite its obvious benefits, implementation of Unicode has progressed slowly. Most U.S. computer users do not stretch the capabilities of the 256-character Windows character set and have no apparent need for a larger set.

For those PC users who do need multilingual capabilities, many software companies have been forward-thinking in their use of Unicode. As early as 1991, Microsoft, IBM, and Apple Computer indicated their intention to incorporate Unicode into the latest release of their products.(42)Microsoft is a good example, as use of its products is widespread. Windows NT 4.0 was built to use full 16-bit Unicode to store internal information and process strings. Windows 95 has a more limited capability with Unicode. It still uses the Windows 3.x code base and is tied to the local character set, so that internal processing is done in the local character set. Applications that run on Windows 95 can, however, utilize Unicode if the strings are translated to the local character set before internal processing is done. This adds overhead to programs that need the multilingual support.

On Windows NT, programs that utilize local character sets rather than the characters in Unicode also need to be translated before processing, though the structure of NT makes the overhead required to do this much less than in Windows 95.(43) The Office 97 version of Microsoft Word (Word 97) will allow files to be saved as UTF-8 and in HTML format.(44) Microsoft's FrontPage Web page editor/manager and Notepad utility allow users to save files in UTF-8 format. UTF-8 is also available in Netscape Navigator 3.0 under Windows 95 and NT 4.0.(45) The Spyglass Mosaic browser supports UTF-8 on Windows 95, as do Alis Tango and AccentSoft's Accent, both based on Spyglass technology.(46)

The Apple Macintosh OS does not currently use the Unicode standard in basic operations. Such support has been planned since the announcement of Unicode, but was not included in the subsequent OS update, System 7. Copeland, soon to become System 8, should add full support for the Unicode character set. Inclusion of multilingual sorting rules should also be part of Copeland.(47)

In addition to operating systems, fonts and font systems are being developed to complement Unicode. The Unicode standard defines only a character set encoding; it does not address issues of sorting, glyph selection, and other high-level text manipulations. These need to be taken care of by the applications and systems built on top of it. On the Apple end, QuickDraw GX and its associated Line Layout Manager currently provider users of MacOS 7.5 with functionality that enhances fonts. These utilities provide automatic kerning and on-the-fly ligature choices, linking characters into combined glyphs where necessary. This glyph selection is important in languages such as Arabic and Hebrew where the position of the character in a word often determines its glyph shape. Worldscript, another Macintosh exclusive, allows text to flow from right to left as in Arabic and Hebrew.(48)

Microsoft has answered Apple's glyph manipulation functionality with TrueType Open. TrueType fonts used in the Windows and Windows NT environments compatible and are based on what they call 8-bit ANSI. According to Microsoft, most Windows TrueType fonts already use Unicode coding internally so they are prepared for the change to Unicode. TrueType Open provides glyph substitution, positioning, and script and language information. It has been available only in the Middle East and Far East versions of Windows 95 with plans in the works for extension to other versions.(49)

For all of these applications of the Unicode Standard, fonts must be created that are compatible with the standard. Windows NT comes with a font called Lucida Sans Unicode, which contains glyphs for 1,752 characters in Unicode. CJK support is notably absent from this font, though it serves other needs respectably. The NT 4.0 CD-ROM does include three additional fonts for CJK that are installed in a separate step. Bitstream is planning to provide a free Unicode-based font, Cyberbit, that includes characters for use in several languages. Additional languages and typefaces will be available for purchase from Bitstream. Fonts for use with Gamma UniType are included in language volumes. If the text's needs extend beyond these glyphs, fonts can be created with such programs as Macromedia Fontographer, available in both Macintosh and PC versions. The latest version of Fontographer, 4.1, allows the creation of fonts with glyphs in their Unicode positions. The Macintosh version has 2,147 prenumbered slots for such characters; the Windows version has 1,267 spaces available.(50)

For those unwilling to wait for Microsoft and Apple to implement Unicode fully, there are many other options. Two useful add-on products com from Gamma Productions and the Institute of Systems Science at the National University of Singapore.(51) Gamma Productions' Gamma UniType integrates with programs running under Microsoft Windows, allowing the user to select languages and appropriate keyboard layouts for producing multi-language documents.(52)Multilingual Application Support Service (MASS), from the Institute of Systems Science, focuses its support on the CJK languages. The Institute offers their product in many flavors of UNIX; a beta version for Microsoft Windows has been available since Oct. 1995. WinMASS adds Chinese, Japanese, Korean, and Tamil capabilities to most Windows applications. Other languages, such as Arabic, Cyrillic, and Greek are planned for the final release version and are already available in the Unix versions. The 16-, 8-, and 7-bit forms of Unicode/10646 are supported in MASS products.(53)

Barriers to Adoption

Changing over to the Unicode/10646 standard will be no simple feat. Many technical and political barriers, as well as simple bigotry, must be overcome before it can take the place of ASCII as the lingua franca of computing. After almost 30 years, the use of ASCII is firmly ingrained in our psyche and in our computer programs. Computing systems in the West are designed to use 7-bit and 8-bit character sets. These character sets have proven quite useful to the groups and nations for which they were created. Software has been hard-coded for use with smaller character sets. Not all computer systems are able to use the larger character size of canonical Unicode or 10646 and network transmission of 16- or 32-bit characters cannot be done without changing to a transformation format. A choice also needs in the form of 10646 to implement: UTF-8, UCS-2, or UCS-4. A font with the full thirty-thousand characters of the BMP would be unmanageable. Smart font system are still needed for glyph substitution and presentation forms of Arabic and other context-sensitive languages.

Pre-Unicode data and data systems also put up barriers. Mapping of old character set to the Unicode set allows the old information to be usable in new environments. In some cases, should that data need to be returned to its original form, the many-to-one problem appears. The USMARC character sets contain more than one instantiation of what have been dubbed "ASCII clones," digits and punctuation that appear separately in the Latin, Cyrillic, Hebrew, and Arabic character sets. Each of these duplicate characters map to a single location in Unicode. On the return trip, mapping back to the original character set, the single Unicode character contains no additional information about where it came from. There is no indication as to which of the two or more possible spaces in the old character set it should go.(54)

A more salient difficulty relates to SGML document access. HTI texts are queried through the OpenText search engine (OT5) formerly known as Pat. OT5 understands only 7-bit characters, 8-bit characters, and EUC. Although OT5 can search on 8-bit characters, there is no way to input them unambiguously across platforms (see Table 1: Windows and Macintosh Character Sets). Most search engines, OT5 included, are used in a crossplatform environment. The lack of a standard interpretation of 8-bit characters is a significant hindrance to the ability of search engines to retrieve documents and text. Characters beyond the initial 128 are removed when searched, regardless of the search engine.

SGML and Character Sets

While the document character set may need to be 7-bit, 8-bit, or EUC so that OT5 can search the text, Unicode and its transformation formats can be used for communicating the results of a OT5 query across the Internet. The HTI is already using a similar dichotomy to encode and display Greek in the Bryn Mawr Classical Reviews.(55) The articles have been encoded in SGML using the Text Encoding Initiative DTD (TEILite) and are searched using OT5. The results of searches can be presented in SGML or HTML form. Using SGML, there are many options for display of the Greek text. For example, stylesheets can describe the font that has the needed glyphs; character entity references (&eacute;) can be mapped or linked to GIFs or font glyphs.

For HTML display, users are given the choice of three mechanisms: beta code, fonts, or GIF images of the Greek glyphs. The underlying character set and text representation in beta code is invisible to users who select either of the other options. The variety of presentation options the HTI can offer is extended with Unicode/10646 and its transformation formats. Many of the characters in HTI texts are ASCII, which fits neatly within UTF-8 in particular (see above). Latin-1 is included via character entity references, which are also mapped to other display formats when necessary. Text sections in Greek are mapped from the original beta code to the display formats described above. A similar strategy has been used by the Perseus Project at Tufts University in offering display options to meet user needs.(56)

If the collections created and supported by the Humanities Text Initiative were only for in-house use, the problems associated with character sets and glyph representations would be nonexistent. HTI texts are often encoded using the Text Encoding Initiative Document Type Definition (DTD), which provides methods for utilizing characters in and outside of the local character set. For needs within the local set, the applicable local character can be inserted in the text directly. Characters not in this character set should be presented as SGML entity references. Suggested names for these entities have been published by the ISO and others, including the TEI. For example, a small 'e' with acute accent may be referenced as &eacute; with the semicolon optional in some circumstances. Entity sets must be declared before characters in that set are used; the é is part of the ISO Latin-1 set, which is declared as follows:

     <!ENTITY %ISOLat1 PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN">

Individual characters with no standard entity name can be declared individually. These characters can be associated with printer commands, which makes them highly situation-specific. Character entity references are typically created using ISO 646:IRV characters; ISO 646 is the simplest form of computer characters and is not likely to be garbled in transit.

The transmission of HTI texts over the Internet complicates this process. With local-use, the variables are all known: the local character set, other available sets, fonts to represent the glyphs, etc. The HTI sends SGML out over the net with character entity references mapped to specified fonts, mostly relying on the commonality of Latin-1 fonts. When only a few non-Latin-1 characters are included, GIFs are sufficient and unambiguous for representation.

Providing multiple options for users to view Humanities Text Initiative materials is the most effective way to ensure that everyone with access to the materials will be able to use them. The flexibility of the systems underlying the text collections and the SGML in which they are stored make multiple display options feasible. Until the Unicode standard has complete support within our user population, it cannot be the only option available to them. This fits with the HTI's efforts to provide HTML versions of its texts while keeping the dynamism and power of the underlying SGML intact.


I expect that the use of Unicode/10646 will increase dramatically in the coming few years for many reasons. Use of the Internet has increased awareness of the problems inherent in the use of multiple character set standards. It has also increased the potential audience for HTI-created texts. The standard was created by and has been embraced in the computer industry. Many products have come on the market with support for some or all of the standard; Microsoft's use of UTF-8 and Unicode, especially in Windows NT, is a boost to the mainstreaming of such products. Fonts to allow display of all characters in Unicode have been slow to arrive. The announced release date for Bitstream's free Cyberbit font has been pushed back over the past year, though Microsoft's Lucida Sans Unicode has sufficient glyphs for most Western languages.

Support and use of the Unicode/10646 standard is the best way for the Humanities Text Initiative to move toward its goals of a completely cross-platform, flexible, and durable method for distributing multilingual text. The Standard is cross-platform, with character codes that return the same glyph in compliant fonts whether a Macintosh, PC, or UNIX computer is used for sending and receiving the text. No one computer type or computer company has control over the content of the character set. There is no need to change the positioning of characters or the basic character repertoire, as the Unicode standard is designed to incorporate all of these characters. If there is a need to add characters that may not be of use to the wider Unicode audience, the standard has the flexibility to allow the additions in the User Defined Area. Durability of Unicode is provided through its transformation formats, which offer safe transit of character data through many intermediate systems. Of particular interest, Unicode/10646 works well for Greek. Characters necessary for the Greek language have been agreed upon by scholars and are included in Unicode, both the Ancient and monotonic versions of the language are stable and generally unchanging, and there are few context-sensitive glyphs like sigma to complicate the rendering process. More generally, the solution to the problem of displaying Greek is the solution to problems in displaying French, Cyrillic, and even Chinese.

The Unicode standard provides a much more satisfying and practical solution than any other option available. GIF images, character set switching, transliteration, and font changes are not able to support all of the characters needed in the HTI in a way that is useful and comprehensive to the end user. The implementation of the Unicode standard in Internet- and SGML-related computing applications brings us closer to true document fidelity worldwide.


Since this paper was researched and written, many changes have taken place in both SGML and Unicode. One of the more salient changes has been the introduction of XML, Extensible Markup Language. XML was designed by a group of SGML experts to crate a simpler SGML for the Internet. The base character set for XML is Unicode. More details on XML and its use of Unicode can be found at http://www.textuality.com/sgml-erb/WD-xml.html. Other technologies that deserve mention here include Bitstream's TrueDoc (http://www.bitstream.com/truedoc.htm) and WebFonts (http://reality.sgi.com/grafica/webfonts/). Internationalization is a dynamic area and changes take place too rapidly for any discussion to be completely up-to-date. A periodic search of Internet sites and monitoring of newsgroups and listservs is necessary for a more thorough understanding of the current solutions and controversies. The of the Web sites linked to in this paper have been verified as correct as of March 14, 1997. There is, of course, no guarantee that these sites will remain at their current locations.


I would like to thank my advisor John Price-Wilkin for guiding me through the process of completing this project, offering critiques and ideas along the way. I would also like to thank Glenn Adams for his clarifications of the complex issues involved in character sets and Unicode.


Abramson, Dean. "Globalization of Windows." Byte vol. 19, no. 11. Nov. 1994.

Adams, Glenn. "Character Set Terminology, SC2 vs. SC18 vs. Internet Standards." April 7, 1995. Available at http://www.stonehand.com/glenn/csetterm1.txt.

Adams, Glenn. "Unicode and Internationalization Glossary." 1993. Available at http://www.stonehand.com/unicode/glosscnt.html.

Aliprand, Joan. "Nonroman Scripts in the Bibliographic Environment." Information Technology and Libraries. vol. 11, no. 2, June 1992.

Aliprand, Joan. "Unicode and ISO/IEC 10646: An Overview" in Automated Systems for Access to Multilingual and Multiscript Library Materials. IFLA Publications 70, 1994.

Andreessen, Marc. "The *World Wide* Web." Jan. 13, 1997. Available at http://home.netscape.com/comprod/columns/techvision/international.html.

Bettels, Jürgen and F. Avery Bishop. "Unicode: A Universal Character Code." Digital Technical Journal. Summer 1993. Available at http://www.digital.com/info/DTJB02/DTJB02SC.TXT.

Butcher, Roger "Multi-lingual OPAC developments in the British Library." Program: Automated Library and Information Systems vol. 27 no. 2 April 1993.

Cain, Jack. "Linguistic Diversity, Computers and Unicode." Paper presented at "Networking the Pacific: An International Forum," in Victoria, BC, Canada, May 5-6, 1995. Available at http://www.idrc.ca/library/document/netpac/abs21.html.

Carrasco Benitez, Manuel Tomas. "Web Internationalization." Available at http://www.crpht.lu/~carrasco/winter/inter.html.

Carrasco Benitez, M.T. "On the Multilingual Normalization of the Web." Presented at the Third International World-Wide Web Conference, Darmstadt, Germany, April 10-14, 1995. Available at http://www.crpht.lu/~carrasco/winter/poster.html.

Clews, John. Language Automation Worldwide: The Development of Character Set Standards. British Library R&D Reports; 5962. Harrogate, North Yorkshire: SESAME Computer Projects, 1988.

Connolly, D. "Character Set Considered Harmful." MIT/WC3. HTML Working Group Internet Draft. May 2, 1995. Available at http://www.w3.org/pub/WWW/MarkUp/html-spec/charset-harmful.html.

"Countdown to System 8." MacUser. July 1995. Available from http://www.zdnet.com/macuser/mu_0795/feature/feature1.html.

Davis, Mark. "UCS Transformation Format 8 (UTF-8)." ISO/IEC JTC1/SC2/WG2 N 1036. August 1, 1994. Available at http://www.stonehand.com/unicode/standard/wg2n1036.html and http://www.stonehand.com/unicode/standard/fss-utf.html.

Everson, Michael. "Today's BMP of ISO/IEC 10606-1." December 12, 1996. Available at http://www.indigo.ie/egt/standards/iso10646/bmp-today-table.html.

Fayen, Emily Gallup. "The ALA Character Set and Other Solutions for Processing the World's Information." Library Technology Reports. vol. 25 no. 2, March-April 1989.

Gamma Productions. "Gamma Productions On-Line Catalog of Products and Services." No date. Available at http://www.gammapro.com/products.html.

Gaylord, Harry E. "Character Entities and Public Entity Sets: Report No. TEI TR1 W4." Jan. 9, 1992.

Gaylord, Harry E. "Character Representation." in Text Encoding Initiative: Background and Context. edited by Nancy Ide and Jean Veronis. Durdrecht, (The Netherlands: Kluwer Academic Publishers, 1995): 51-61. reprinted from Computers and the Humanities, vol. 29, pp. 51-73, 1993.

Gaylord, Harry. Email communication of Nov. 11, 1996.

Goldsmith, David, and Mark Davis. "UTF-7: A Mail-Safe Transformation Format of Unicode." Network Working Group Internet Draft. March 11, 1997. Available at ftp://ietf.org/internet-drafts/draft-goldsmith-utf7-02.txt.

Institute of Systems Science, National University of Singapore. "Multilingual Application Support Service." Available at http://www.iss.nus.sg/RND/MLP/Projects/MASS/MASS.html.

ISO/IEC. "Amendment 1: UCS Transformation Format 16 (UTF-16)." ISO/IEC JTC1/SC2/WG2 N 1035. August 1, 1996. Available at http://www.stonehand.com/unicode/standard/wg2n1035.html.

ISO/IEC, Subcommittee 2 and Subcommittee 18 of JTC 1, Information technology. "Character/Glyph Model." Available at http://www.dk.net/JTC1/SC2/WG2/docs/N1411.doc.

Kano, Nadine. "TrueType Open Extends Support for International Typography." Going Global. Available from http://www.microsoft.com/globaldev/gbl-gen/codesets/truetype.htm. Reproduced from the November/December 1995 issue of the Microsoft Developer Network News.

Kano, Nadine. "Yes, Virginia, Windows 95 Does Do Unicode!" Going Global. July/Aug. 1995. Available from http://www.microsoft.com/globaldev/gbl-gen/codesets/unicw95c.htm. Reproduced from the July/August 1995 issue of the Microsoft Developer Network News.

Lazinger, Susan S. and Judith Levi. "Multiple Non-Roman Scripts in ALEPH -- Israel's Research Library Network." Library Hi Tech. vol. 14 no. 1, 1996.

Library of Congress. "About MARBI." Jan. 1, 1996. Additional information is available at http://lcweb.loc.gov/marc/marbi.html.

Library of Congress. "UCS and USMARC Mapping." MARBI Discussion Paper No. 73. Dec. 6, 1993. Available via Gopher at gopher://marvel.loc.gov:70/00/.listarch/usmarc/dp73.doc.

Mackenzie, Charles. Coded Character Sets, History and Development. Reading, Mass.: Addison-Wesley Publishing Co., 1980.

Macromedia. Fontographer User's Guide. Version 4.1. 1996.

MARBI Character Set Subcommittee. "USMARC Character Set Issues and Mapping to Unicode/UCS." Proposal No. 96-10. Revised July 22, 1996. Available via Gopher at gopher://marvel.loc.gov:70/00/.listarch/usmarc/96-10.doc.

McClure, Wanda L. and Stan A. Hannah. "Communicating Globally: The Advent of Unicode." Computers in Libraries. vol. 15 no. 5, May 1995.

Microsoft. "Character Sets." Going Global. April 1996. Available from http://www.microsoft.com/globaldev/gbl-gen/codesets/charsets.htm.

Microsoft. Microsoft Word User's Guide, Appendix A: Character Sets.

Miller, L. Chris. "Transborder Tips and Traps." Byte. vol. 19 no. 6, pp. 93-102.

Nichol, Gavin T. "The Multilingual World Wide Web." June 1994. Available at http://www.ebt.com/docs/multling.html.

Peruginelli, Susanna, Giovanni Bergamin, and Pino Ammendola. "Character sets: towards a standard solution?" Program: Automated Library and Information Systems. vol. 26 no. 3, July 1992.

Petzold, Charles. "Move Over, ASCII! Unicode Is Here." PC Magazine. v. 12, no. 18, Oct. 26, 1993.

Pratley, Chris. Microsoft, Inc. Quoted in Misha Wolf's message to the Unicode listserv dated Nov. 7, 1996.

Sheldon, Kenneth M. "ASCII Goes Global." Byte. vol. 16 no. 7, July 1991, pp. 110-11.

Text Encoding Initiative Guidelines for Electronic Text Encoding and Interchange.

Tresman, Ian. The Multilingual PC Directory. 2nd edition. Borehamwood, Herts., UK: Knowledge Computing, 1994.

Unicode, Inc. "General Information." Available at http://www.stonehand.com/unicode/standard/general.html.

Unicode, Inc. "Unicode and Internationalization Glossary." Available at http://www.stonehand.com/unicode/glosscnt.html.

Unicode, Inc. The Unicode Standard, Version 1.0, Volume 1. 1991; The Unicode Standard, Version 1.0, Volume 2. 1992.

Unicode, Inc. The Unicode Standard, Version 2.0, 1995.

Vacca, John. "Unicode Breaks the ASCII Barrier." Datamation. vol. 27, no. 15. Aug. 1, 1991.

Yergeau, F. et. al. "Internationalization of the Hypertext Markup Language." IETF Draft html-i18n-05. Network Working Group, Internet Draft, Aug. 7, 1996. Available from http://www.alis.com:8085/ietf/html/draft-ietf-html-i18n-05.txt.

Appendix A: UTF-8 in Netscape Navigator

Appendix B: Glossary


1. A character encoding is a description of the scheme of assigning codes to individual characters. The term also applies in an SGML context, but has a slightly different meaning there. [BACK]

2. Discussion derived from Emily Gallup Fayen, "The ALA Character Set and Other Solutions for Processing the World's Information," Library Technology Reports (March-April 1989): 257. [BACK]

3. Harry E. Gaylord, "Character Representation." in Text Encoding Initiative: Background and Context, ed. Nancy Ide and Jean Veronis (Durdrecht, The Netherlands: Kluwer Academic Publishers, 1995), 60, ftn 4. Gaylord indicates a preference for the term "coded character set" in international and national standards. I will use "character set" in this report for brevity. [BACK]

4. Charles Mackenzie, Coded Character Sets, History and Development. (Reading, MA: Addison-Wesley Publishing Co., 1980), 497. [BACK]

5. Mackenzie, Coded Character Sets, 211-17. See below for more on ASCII. [BACK]

6. More information on glyphs and characters can be found in the Character/Glyph Model document at http://www.dk.net/JTC1/SC2/WG2/docs/N1411.doc. [BACK]

7. Gaylord, "Character Representation," 53. [BACK]

8. For a history of character sets and the activities of standards bodies, see Mackenzie, Coded Character Sets. [BACK]

9. John Clews, Language Automation Worldwide: The Development of Character Set Standards. (Harrogate, North Yorkshire: SESAME Computer Products, 1988), 36. Others have places this figure at around 450. [BACK]

10. Glenn Adams, Correspondence of Jan. 24, 1997. [BACK]

11. The replaceable characters are #, $, @, [, \, ], ^, `, {, |, }, and ~. Clews, Language Automation Worldwide, 24. The dollar sign replaced the international currency symbol in ISO 646 IRV:1991. Gaylord, "Character Representation," 53. [BACK]

12. Joan Aliprand, "Nonroman Scripts in the Bibliographic Environment," Information Technology and Libraries 11, no. 2 (June 1992): 112. [BACK]

13. Microsoft. "Character Sets." Going Global (April 1996). Available from http://www.microsoft.com/globaldev/gbl-gen/codesets.htm. [BACK]

14. There is an additional type of standard, the de facto standard. De facto standards are utilized by a large user group but do not have any formal means of standardization. Clews lists the USMARC character set as de facto, though it has a formal standardization channel in the MARBI Working Group of the American Library Association. [BACK]

15. Clews, Language Automation Worldwide, 31-35. This section includes discussion of and charts for several of these national MARC character sets. [BACK]

16. Library of Congress. "About MARBI" (Jan. 1, 1996). Additional information is available at http://lcweb.loc.gov/marc/marbi.html. [BACK]

17. Harry Gaylord, Email communication of Nov. 11,1996. The status of ISO 8859-4 is confusing: parts of the standard have been incorporated in 8859-10 and an alternative 8859-13 has been proposed for the languages that were covered by 8859-4. [BACK]

18. For complete tables of each character set, see Microsoft Word User's Guide, Appendix A: Character Sets, 785-94. [BACK]

19. Adams, Correspondence of Jan. 24, 1997. [BACK]

20. Clews, Language Automation Worldwide, 88-91. [BACK]

21. Aliprand, "Nonroman Scripts in the Bibliographic Environment," 110. [BACK]

22. Jürgen Bettels and F. Avery Bishop, "Unicode: A Universal Character Code," Digital Technical Journal (Summer 1993). Available at http://www.digital.com/info/DTJB02/DTJB02SC.TXT. [BACK]

23. Unicode, Inc. "Unicode and Internationalization Glossary." Available at http://www.stonehand.com/unicode/glosscnt.html. [BACK]

24. Kenneth M. Sheldon, "ASCII Goes Global," Byte 6 no. 7 (July 1991): 110-11. [BACK]

25. Information Technology -- Universal Multiple-Octet Coded Character Set (UCS), ISO/IEC 10646. [BACK]

26. The Unicode Standard, Version 1.0, Volume 1. 1991; The Unicode Standard, Version 1.0, Volume 2. 1992. [BACK]

27. Details of these octets are not presented here; Unicode's group and plane octets both have the value of 00. See Joan Aliprand's "Unicode and ISO/IEC 10646: An Overview" in Automated Systems for Access to Multilingual and Multiscript Library Materials. IFLA Publications 70, 1994. pp. 87-102. [BACK]

28. Based on a graphic in Joan Aliprand's article "Unicode and ISO/IEC 10646: An Overview" in Automated Systems for Access to Multilingual and Multiscript Library Materials. IFLA Publications 70, 1994. This is the BMP as it was in Unicode 1.0, not in version 2.0, and some changes have been made in the allocation of space. Michael Everson has created a more current version of the BMP, "Today's BMP of ISO/IEC 10606-1," available at http://www.indigo.ie/egt/standards/iso10646/bmp-today-table.html. [BACK]

29. Unicode, Inc. "General Information." Available at http://www.stonehand.com/unicode/standard/general.html. In Unicode 2.0, a total of 47,399 of the 65,536 codes have been assigned. Of these, 38,885 are graphic, formatting, or special character, 64 are controls, 2 are non-use specials, 6400 are private use, and 2048 are for use with UTF-16. An additional 9410 characters have been approved and are in the balloting stage. (Adams, Correspondence of Jan. 24, 1997.) [BACK]

30. The Unicode Standard, Version 1.0, Volume 1, 4. [BACK]

31. ISO 6937 was designed for text communication of current European languages. Clews, Language Automation Worldwide, 52-5. [BACK]

32. MARBI Character Set Subcommittee, "USMARC Character Set Issues and Mapping to Unicode/UCS," Proposal No. 96-10, revised July 22, 1996. Available via Gopher at gopher://marvel.loc.gov:70/00/.listarch/usmarc/96-10.doc. See also "UCS and USMARC Mapping," Discussion Paper No. 73, Dec. 6, 1993. Available via Gopher at gopher://marvel.loc.gov:70/00/.listarch/usmarc/dp73.doc. [BACK]

33. The Unicode Standard, Version 1.0, Volume 2, 2. [BACK]

34. Adams, Correspondence of Jan. 24, 1997. [BACK]

35. David Goldsmith and Mark Davis, "UTF-7: A Mail-Safe Transformation Format of Unicode," Network Working Group Internet Draft (October 14, 1996). Available at ftp://ietf.org/internet-drafts/draft-goldsmith-utf7-02.txt. [BACK]

36. Mark Davis, "UCS Transformation Format 8 (UTF-8)," ISO/IEC JTC1/SC2/WG2 N 1036 (August 1, 1994). Available at http://www.stonehand.com/unicode/standard/wg2n1036.html and http://www.stonehand.com/unicode/standard/fss-utf.html. [BACK]

37. ISO/IEC, "Amendment 1: UCS Transformation Format 16 (UTF-16)," ISO/IEC JTC1/SC2/WG2 N 1035 (August 1, 1996). Available at http://www.stonehand.com/unicode/standard/wg2n1035.html. [BACK]

38. F. Yergeau et. al., "Internationalization of the Hypertext Markup Language," IETF Draft html-i18n-05. Available from http://www.alis.com:8085/ietf/html/draft-ietf-html-i18n-05.txt, 18. [BACK]

39. Dean Abramson, "Globalization of Windows," Byte 19, no. 11 (Nov. 1994): 178. [BACK]

40. Charles Petzold, "Move Over, ASCII! Unicode Is Here," PC Magazine 12, no. 18 (Oct. 26, 1993): 374. [BACK]

41. Aliprand, "Nonroman Scripts in the Bibliographic Environment," 117. [BACK]

42. John Vacca, "Unicode Breaks the ASCII Barrier," Datamation 27, no. 15 (Aug. 1, 1991): 56. [BACK]

43. Nadine Kano, "Yes, Virginia, Windows 95 Does Do Unicode!" Going Global (July/Aug. 1995). Available from http://www.microsoft.com/globaldev/gbl-gen/codesets/unicw95c.htm. [BACK]

44. Chris Pratley, Microsoft, Inc. Quoted in Misha Wolf's message to the Unicode listserv dated Nov. 7, 1996. [BACK]

45. The registry needs to modified for Navigator to be able to use UTF-8. This encoding option is greyed out otherwise. Instructions for changing the registry are included as Appendix A. For Netscape's latest statement on internationalization, see Marc Andreessen's piece at http://home.netscape.com/comprod/columns/techvision/international.html. [BACK]

46. Adams, Correspondence of Jan. 24, 1997. Spyglass Mosaic - http://www.spyglass.com/products/smosaic/; Alis Tango - http://www.alis.com/tango/tango.en.html; AccentSoft Accent - http://www.accentsoft.com/press/homepage.htm. [BACK]

47. "Countdown to System 8," MacUser (July 1995). Available from http://www.zdnet.com/macuser/mu_0795/feature/feature1.html. [BACK]

48. Ibid. [BACK]

49. Nadine Kano, "TrueType Open Extends Support for International Typography," Going Global. Available from http://www.microsoft.com/globaldev/gbl-gen/codesets/truetype.htm. [BACK]

50. Macromedia. Fontographer User's Guide. Version 4.1 (1996): 198. [BACK]

51. A listing of additional products that support the Unicode Standard is available at http://www.stonehand.com/unicode/products.html. [BACK]

52. Gamma Productions. "Gamma Productions On-Line Catalog of Products and Services." No date. Available at http://www.gammapro.com/products.html. [BACK]

53. Institute of Systems Science, National University of Singapore, "Multilingual Application Support Service." Available at http://www.iss.nus.sg/RND/MLP/Projects/MASS/MASS.html. [BACK]

54. MARBI Character Set Subcommittee, "USMARC Character Set Issues and Mapping to Unicode/UCS." Proposal No. 96-10, revised July 22, 1996. Available via Gopher at gopher://marvel.loc.gov:70/00/.listarch/usmarc/96-10.doc. [BACK]

55. HTI's online version of Bryn Mawr Classical Reviews is not yet available to the public. [BACK]

56. The Perseus Project can be found at http://medusa.perseus.tufts.edu/index.html. [BACK]