Sutton-Slevinski Collaboration S. Slevinski
Internet-Draft SignPuddle
Intended status: Informational November 05, 2012
Expires: May 09, 2013

The SignPuddle Standard for SignWriting Text


For concreteness, because the universal character set is not yet universal, and because an international standard for the internet community should be documented and stable, this I-D has been released with the intention of producing an RFC to document the character use and naming conventions of the SignWriting community on the Internet.

The SignWriting Script is an international standard for writing sign languages by hand or with computers. From education to research, from entertainment to religion, SignWriting has proven useful because people are using it to write signed languages. The SignWriting Script has two major families: Block Printing for the reader and Handwriting for the writer. The script encoding model presented in this document evolved from the Block Printing half of the SignWriting Script.

The SignWriting Text encoding model encompasses the Block Printing family of the SignWriting Script. The plain text model has been stable since January 12th, 2012. The rich text model is currently approaching a usable beta.

The ad hoc graphemes of informal SignWriting were first created in 1974. Ad hoc graphemes are still used in the handwriting family. The standardized symbols of computerized Block Printing text began in 1986. After several generations of writers and standardized symbolsets, the ISWA 2010 has been optimized and refined as a 16-bit coded character set with several isomorphic encodings based on an ordered hierarchy with 6 degrees of significance. The International SignWriting Alphabet 2010 is a mathematical symbolset that has been stable since its initial release on May 11th, 2010.

The SignPuddle Standard for SignWriting Text is an open and freely available encoding model for sign language as text. The licenses include the Open Font License for the fonts, Creative Commons by-sa (Attribution, Share Alike) for the documentation, and the GPL for the software implementation. The technological infrastructure is 63% completed and should be fully realized by the time this I-D has become an RFC. SignPuddle Online contains almost 1 million examples of 2-dimensional signs written by the internet community. Each logogram has a mathematical name which describes the freeform placement of the symbols. These strings are the written record of the sign. This standard and emerging infrastructure are used for the sign language Wikipedia project on Wikimedia Labs. This standard is being integrated with the SignTyp linguistic coding system developed by Rachel Channon through an NSF grant. This standard was the origin for the alternate Unicode proposals.

For Unicode, the current use of the Private Use Area font characters is documented. A character proposal for plane 1 is included that is isomorphic with the characters that are currently used by the community.

Three appendices discuss additional topics to the standard. The first discusses the Modern SignWriting theory and example document, stable since January 12, 2012. The second discusses the founding principles of Cartesian SignWriting: a script encoding model for SignWriting Block Printing. The third discusses a common framework for written sign language grammar.

This memo concretely defines a conceptual character encoding map for the Internet community. It is published for reference, examination, implementation, and evaluation. Distribution of this memo is unlimited.

Status of This Memo

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This Internet-Draft will expire on May 09, 2013.

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Table of Contents

1. Introduction

For concreteness, because the universal character set is not yet universal, and because an international standard for the internet community should be documented and stable, this I-D has been released with the intention of producing an RFC to document the character use and naming conventions of the SignWriting community on the Internet.

The SignWriting Script is an international standard for writing sign languages by hand or with computers. From education to research, from entertainment to religion, SignWriting has proven useful because people are using it to write signed languages.

Sign languages are fundamentally different than spoken language in the quality of the segments in the stream of human speech. The SignWriting Script uses 2-dimensional logograms with freeform symbol placement to capture the spatial and simultaneous segments in the stream of signed language speech.

The SignWriting fonts and standards are freely and openly available, with no royalties or restrictions. This information is provided to promote a complete solution for an open culture in written sign language.

1.1. Overview

The SignPuddle Standard for SignWriting Text is an emerging standard intended for the internet community. This memo concretely defines a fully developed model for reference, examination, implementation, and evaluation. Distribution of this memo is unlimited.

The fonts are officially available. The prerelease of the SignWriting Icon Server is available on Github, hosted on SignBank and hosted on Wikimedia Labs. The status of the infrastructure was 63% on November 2nd, 2012.

Section 1 Introduction: includes a discussion of terminology, historical background, current usage, and this overview of the document.

Section 2 SignWriting Script: includes a general discussion of the SignWriting script. Both the Block Printing and the Handwriting families are discussed.

Section 3 SignWriting Text: includes a general discussion of the plain text of logograms and the rich text of styling.

Section 4 ISWA 2010: discusses the SignWriting grapheme, symbolset, and symbol encoding of the ISWA 2010. Symbols are visually iconic, uniquely identified, and organized in a layered hierarchy.

Section 5 SignPuddle Standard: defines the licenses, infrastructure, and the data available.

Section 6 Unicode Integration: discusses the private use area font characters and the proposed characters on plane 1.

Appendix A Modern SignWriting: discusses the theory and example document released on January 12th, 2012.

Appendix B Cartesian SignWriting: presents a script encoding model for SignWriting Block Printing. Formal structures for logographic sign are mixed with punctuation to form text.

Appendix C Theory of SignWriting Grammar: discusses the common and possible script encoding models for written sign language.

1.2. Historical Foundation

In 1966, Valerie Sutton invented the DanceWriting notation, which was the precursor to the entire Sutton MovementWriting System.

in 1974, Valerie Sutton invented the SignWriting Script. The subsequent development of the script was driven by input from readers and writers, both hearing and Deaf.

From 1974 to 1986 SignWriting Script was written exclusively by hand. During this time the use of the script spread around the world, and to this day it continues to be written on paper and chalkboard.

In 1981, the development of SignWriting Block Printing evolved rapidly with the publication of the SignWriting Newsletter, which was published from 1981 to 1984.

In 1984 Emerson and Stern Associates received a grant to develop a word processor for SignWriting Block Printing. The resulting software, which operated on the Apple II, supported only a minor subset of the SignWriting system. It was not subsequently used, and received no further development.

In 1986, Richard Gleaves designed and developed SignWriter as a word processor for SignWriting Block Printing. SignWriter introduced the keyboard typing model and a symbol encoding system which served as the basis for subsequent encoding systems. The initial version was for the Apple IIe, and the resulting symbolset was limited by the 128KB memory limit.

By 1995, SignWriter had been ported to MS-DOS and expanded to support multiple languages, an integrated sign dictionary, and the full SSS-95 symbolset. SignWriter DOS was distributed on the internet, and achieved widespread international use.

In 1999, the SSS-99 symbolset was created for SignWriter Java. The revamped symbolset was created without the limitations imposed upon the SSS-95.

In 2002, the SSS-2002 symbolset reorganized the structure of the symbols imposing a multi level hierarchy with the modern symbol ID. The SSS-2002 was the first symbolset used in the SignBank 2002 application by Todd Duell.

In 2004, the SSS-2004 symbolset was created after reaching widespread international use. The SSS-2004 was the first symbolset used in the SignPuddle application by Steve Slevinski. This symbolset was expanded to include international MovementWriting concepts and became known as the International MovementWriting Alphabet.

September 12, 2008, Valerie Sutton and Steve Slevinski released the ISWA 2008 under the open font license. The International SignWriting Alphabet 2008 was a major refactoring of the IMWA concept by eliminating the general MovementWriting symbols and focusing on the SignWriting script. Valerie organized and named 37,811 unique symbols. Steve analyzed and formatted the ISWA 2008, creating a 16-bit coded character set called the x-ISWA-2008. Steve also created the first iteration of Cartesian SignWriting as a script encoding model.

The ISWA 2008 was used in a production setting for a year and a half without issue. In 2010, the ISWA 2008 was updated. 576 unused symbols had a palm facing irregularity which needed to be fixed. General size and shape of the symbols did not change.

May 11th, 2010, Valerie and Steve released the ISWA 2010. The ISWA 2010 was designed as a focused refactor of the ISWA 2008 concepts. The update included a restructured hierarchy, better movement symbols, elimination of variation defects, addition of new hand shapes, and removal of hand shape variations. Revision 2 of Cartesian SignWriting script encoding model was released for the ISWA 2010. The symbolset and encoding have been stable since release, with only a cosmetic fix for symbol 01-06-017-01-03-10.

June 22nd, 2010, Steve refactored the coded character set as 12-bit rather than 16-bit to improve searching. The updated script encoding model was called Cartesian SignWriting revision 3.

October 20th, 2010, the initial release of the ISWA 2010 Font Reference. Since then, 2 years of stability and growth.

February 23rd, 2011, the addition of SVG using polygon line tracing.

September 19th, 2011, the complete SVG Refinement by Adam Frost.

January 12th, 2012, the fully realized character encoding model for SignWriting Text.

May 2nd, 2012, added database fonts.

November 1st, 2012, the prerelease of the SignWriting Icon Server.

1.3. Current Usage

SignPuddle Online contains almost 1 million examples of 2-dimensional signs written by the internet community. Each logogram has a mathematical name that describes the freeform placement of the symbols. These strings are the written record of the sign. XML files organize these names by language and purpose. The ASL Dictionary has over 9 thousand entries.

This standard and emerging infrastructure are used for the sign language Wikipedia project on Wikimedia Labs (Section 5.3.2). This standard is being integrated with the SignTyp linguistic coding system developed by Rachel Channon through an NSF grant (Section 5.3.3). This standard was the origin for the alternate Unicode proposals. Compatibility with this standard is highly encouraged to efficiently leverage sign language as text.

For Unicode, the current use of the Private Use Area font characters is documented. A character proposal for plane 1 is included that is isomorphic with the characters that are currently used by the community.

2. SignWriting Script

The SignWriting Script is the universal and complete solution for written sign language. It has been applied to a wide and deep international community of many sign languages including: American Sign Language, Arabian Sign Languages, Australian Sign Language, Bolivian Sign Language, Brazilian Sign Language, British Sign Language, Catalan Sign Language, Colombian Sign Language, Czech Sign Language, Danish Sign Language, Dutch Sign Language, Ethiopian Sign Language, Finnish Sign Language, Flemish Sign Language, French-Belgian Sign Language, French Sign Language, German Sign Language, Greek Sign Language, Irish Sign Language, Italian Sign Language, Japanese Sign Language, Malawi Sign Language, Malaysian Sign Language, Maltese Sign Language, Mexican Sign Language, Nepalese Sign Language, New Zealand Sign Language, Nicaraguan Sign Language, Norwegian Sign Language, Peruvian Sign Language, Philippines Sign Language, Polish Sign Language, Portugese Sign Language, Quebec Sign Language, South African Sign Language, Spanish Sign Language, Swedish Sign Language, Swiss Sign Language, Taiwanese Sign Language, and Tunisian Sign Language.

Initially developed in 1974, the script was written exclusively by hand for 12 years. Since then the script has spread around the world and continues to be written on paper and chalkboard.

In 1981, SignWriting Publishing rapidly evolved with Block Printing. In 1986, computerization of the SignWriting Block Printing began. The current symbol encoding of the ISWA 2010 has been stable since the font release on October 20th, 2010. The current character encoding model has been stable since the initial release of Modern SignWriting on January 12th, 2012.

2.1. 2-Dimensional Logograms

A founding principle of the SignWriting Script is that signs are written in 2-dimensional signboxes. The size of the signbox varies with the symbols written inside. Both block printing and handwriting use 2-dimensional logograms.

Inside of a 2-dimensional signbox, the symbols are placed in a freeform, 2-dimensional arrangement. This feature of the script expresses spatial relation directly.

2.2. Viewpoints, Planes, & Perspectives

Writing based on vision uses two viewpoints: receptive and expressive. The receptive viewpoint is based on the idea of receiving an image. For the receptive viewpoint, the right hand of a signer will be written on the left side of the canvas. When SignWriting is used for transcription, the receptive view is most often used. The related writing systems of DanceWriting and MovementWriting normally use the receptive viewpoint.

The expressive viewpoint is based on the idea of expressing a concept. For the expressive viewpoint, the right hand of a signer will be written on the right side of the canvas. When SignWriting is used for authorship, the expressive view is most often used.

The are two main writing planes: the front wall (Frontal Plane) and the floor (Transverse Plane). The choice of writing plane can affect the shape of the graphemes, such as the fill pattern for the hand graphemes or the tail for the movement arrow graphemes.

There are two perspectives: front and top. The front perspective is a straight on view of/from the signer. The top perspective is a top-down view of the signer. Usually, a cluster will be written from a single perspective.

2.3. Block Printing

Block printing is only half of the SignWriting Script. Block printing is based on the iconic symbols of the symbol set. Each of the iconic symbols is structured, standardized, and highly featural. Block printing is used in education, publishing, and is the basis of the computerized model.

Valerie Sutton writes, "SignWriting Printing is easy to read. It is designed for the reader. The Printing can be written by hand as well as by computer. If I am writing a letter to a friend in ASL, I write the letter in SignWriting Printing, taking the time to make sure that my handwritten-symbols are easy and clear to read. I try to write as clearly as if I were using a computer. Of course it is slower, but it is worth it, knowing that my friend will be able to read my letter!"

2.3.1. Education

Kids all over the earth are learning block printing thanks to Valerie Sutton and the material she donates though the Center for Sutton Movement Writing.

2.3.2. Publishing

The history of SignWriting Publishing had a rapid development between 1981 and 1984 with the SignWriter Newspaper. Patience and concentration was needed to write neat enough for publication. Stencils and wax transfer symbols were used in painstaking work. Typesetters could consistently reproduce the iconic symbols.

Discussions during early publishing history were a catalyst for developing a way to type sign language.

The SignWriter Newspaper suspended in 1984 and resumed publication as a typed SignWriter Newsletter in 1989.

2.3.3. Computerized

Block printing is the basis of the computerized SignWriting model.

Read about the Historical Foundation in section 2.C of Modern SignWriting.

Computerized SignWriting is important, but there is so much more to the SignWriting Script.

2.4. Beautiful Handwriting

SignWriting Handwriting has always been a part of the script.

Valerie Sutton writes, "SignWriting Handwriting is easier to write by hand, than the Printing. It is designed for the writer. There are several variations of Handwriting, and since most of the time, the writer is only writing for private notes, some writers create their own shortcuts that work just for them...and that is fine!"

2.4.1. Cursive

A popular form of SignWriting is cursive. It can be shared among a groups of writers or it can be individualized and personal. Cursive writing is designed to have fluid marks and a natural flow. Cursive writing may use fewer features than the iconic symbols, but should be related to an iconic symbol in appearance and meaning. Once developed, this style of writing is great for taking notes in a class.

2.4.2. Shorthand

Shorthand is a skill of the proficient writer. They can write SignWriting shorthand quickly and naturally.

In 1982, Sign Language Stenographers could record sign language with SignWriting Shorthand at normal signing speed. Time tests proved practice and special training were required. The marks they write are personal style of quick and efficient strokes with a highly developed reception to what signifies meaning. They understand the iconic symbols of the SignWriting Script, but their marks are personal reminders rather than a fully developed text.

The shorthand in and of itself is often an incomplete representation of the gestures that were experienced. The shorthand writing can be thought of as a short-term memory device. Often shorthand notes must be revised and extended at a later time, the sooner the better.

2.4.3. Afterward

Online, we experience the block printing branch of SignWriting.

I hope that we do not forget or loose sight of the handwriting branch. Faster texting online would mean an even smaller incentive to learn handwriting or improve our penmenship.

There is a thriving handwriting community for SignWriting that exists throughout the world. They use SignWriting Handwriting on a daily basis as a natural part of their lives. Humans are creatures of language. A written form of language is a valuable tool.

3. SignWriting Text

SignWriting Text is iconic. It specifies properties in common between forms. It is diagrammatic with defined relationships and simple structures. It clarifies likenesses that are topologically similar.

SignWriting Plain Text is stable and fully developed. This document cements this standard for the Internet community with regards to the plain text strings. The plain text model defines several compatible coded character sets and character encoding forms. A sequential list of characters is used as a plain text string.

Plain text strings use character patterns to represent mathematically sized logograms. This robust plain text encoding model separates visual display, layout issues, and regular expression searching. This enables a distributed client-server model of iconic SignWriting information using mathematical names and visual images.

The rich text model defines styling using basic CSS rules for HTML or MediaWiki markup. The rich text model is quickly approaching a usable beta.

3.1. Mathematical Name

The mathematical name of a logographic sign is a plain text string of characters. This encoding model makes explicit those features which can be effectively and efficiently processed. Formal languages and regular expressions are used to solve fundamental problems.

3.2. Visual Image

The visual image of a logographic sign is a 2-dimension arrangement of symbols inside of a sign box. The sign box has a defined width, height, and 2-dimensional center that can be calculated from the plain text.

Raster images are supported with PNG (Portable Network Graphics). Vector images are supported with SVG (Scalable Vector Graphics).

3.3. Infrastructure

The infrastructure on the internet for SignWriting Text leverages a client-server model where the client requests information and the server provides. By splitting the world of client-server, we created a powerful model which is structured, productive, and scalable. The source code is hosted on Github. The font collection is hosted on The data collection is available from SignPuddle Online hosted on SignBank.

The main SignWriting Icon Server is available on SignBank. This server has all of the fonts installed and has full access to the SignPuddle Online data.

A secondary server is available on Wikimedia Labs for the ASL Wikipedia Project and other Wikimedia projects.

Individuals can run their own SignWriting Icon Server, private networks can have a SignWriting Icon Server, and we can have SignWriting Icon Servers freely available on the internet.

The client side is most often a browser. The client side uses the mathematical names of SignWriting Plain Text for general text processing. Searching, sorting, and layout are easy client side tasks. The structure of a page can be quickly created. If the image server lags, it is of no concern to the client. The images appear where and how they are should without any jumping or bouncing. Simple math and basic CSS rules determine layout.

Client side programming is simplified by using a SignWriting Icon Server. SignWriting Text can be implemented on a website or in applications with less programming. Plugins and extensions can focus on the math and CSS style rules for rich text layout without having to reinvent the wheel of logographic images.

Visit for the status of the infrastructure.

3.4. Character Encoding Scheme

Encoding schemes define how a character is written as a sequence of bytes. SignWriting Text can use encoding schemes based on either: ASCII or Unicode.

Given a sequence of bytes representing text and a stated character encoding scheme, a string of characters is unambiguous and it is easy to recreate a sequence of characters as required for plain text.

3.4.1. ASCII

Every logographic sign has a mathematical name in ASCII. ASCII is universally supported. The ASCII names are authoritative and easy to identify. Searching with regular expressions is 4 times faster in ASCII that the equivalent Unicode. Hexadecimal

Hexadecimal is base 16, but in this context is a subset of ASCII. In this reference, hexadecimal characters are single digits between 0-9 along with a-f. For code points in x-Binary-SignWriting, x-Character-SignWriting, and standard Unicode reference, the upper case A-F upper case hex characters are used. For the lite markups of KSW and FSW, the hex values are always lower case. The upper case ASCII in the lite markup is reserved for structure, such as ABLRMSQ.

3.4.2. Unicode

Every logographic sign has a temporary name of Unicode PUA characters for client side font handling. The use of the Unicode PUA demonstrates the necessity and the capability of the proposed character set.

3.5. Coded Character Set

A character is a fundamental building block of digital data. A character's smallest representation is a binary representation of a code point found in a character set. A string is an ordered sequence of characters, which is nothing more that a list of code points.

3.5.1. x-ISWA-2010

The x-ISWA-2010 is a 16-bit character set that covers each symbol of the ISWA 2010. A 16-bit code is an integer between 0 and 65,535. This type of value is perfect for a primary key for database lookup or other integer index. Through a simple formula, any symbol identification can be transformed into a unique 16-bit codepoint. Font software using the SQLite fonts rely on the x-ISWA-2010 coded character set.

Read about the symbol set and the symbol encoding design in Modern SignWriting.

3.5.2. x-Binary-SignWriting

The x-Binary-SignWriting is a 12-bit character set that covers the characters of SignWriting Plain Text. It is possible to write the name of a logographic sign with binary data. This is more of a theoretical advantage because we don't write with 12-bit characters. This form is most useful for the translation to Private Use Area Unicode.

Read about the coded characters set and the string patterns in Modern SignWriting.

3.5.3. x-Character-SignWriting

The x-Character-SignWriting is a character set for SignWriting in Unicode. Take the characters of the x-Binary-SignWriting coded character set and add hexadecimal value FD700. The PUA font characters are defined in Section 6.

3.6. Character Encoding Form

The specifics of the character encoding forms are contained in Modern SignWriting, section 8: Text Encoding, section 9: Regular Storage Form, and section 10: Variant Display Form.

3.6.1. BSW - Binary SignWriting

Binary SignWriting uses fixed-width hexadecimal characters from the the 12-bit coded character set x-Binary-SignWriting. Each character is written with 3 hexadecimal digits. Structures are identified with one characters (3 digits), symbols are identified with 3 characters (9 digits), numbers are identified with 1 character (3 digits), and coordinates are identified with 2 characters (6 digits). The name of a sign is a patterned string. The character definitions are available in Modern SignWriting, section 8: Repertoire and Coded Character Set.

3.6.2. CSW - Character SignWriting

Character SignWriting uses Private Use Area Unicode characters to create a logographic sign with a mathematical name. The character definitions are available in Modern SignWriting, section 8: Repertoire and Coded Character Set.

3.6.3. FSW - Formal SignWriting

Formal SignWriting uses a lite markup to create a string that represents a sized logogram with a regular structure. ASCII characters are used to identify structure, symbols, and coordinates. The lite markup of FSW is covered in Modern SignWriting, section 9: Lite Markup. A structured query language for FSW is covered in section 9: Query String.

3.6.4. KSW - Kartesian SignWriting

Kartesian SignWriting uses a lite markup to create a string that represents a variant display area. ASCII characters are used to identify structure, symbols, and coordinates. The lite markup in general is covered in Modern SignWriting, section 8: Lite Makrup. The specific forms of KSW are covered in section 10: variant display forms.

3.7. Query Language

The query language is an ASCII lite markup similar to FSW used to search. A query will compile to a series of regular expression to search a section of text to find similar or exact sign matches. Modern SignWriting section 9 clearly illustrates the searching available and the associated regular expression technology.

The query string is a concise representation for a much larger set of regular expression statements. The query string permits several types of searches for symbols, ranges and spatial relation.

4. ISWA 2010

The ISWA 2010 is the abstract symbolset for the x-ISWA-2010 coded character set. The symbols are visually iconic, uniquely identified, and organized in a layered hierarchy (Section 4.3).

The x-ISWA-2010 is a 16-bit coded character used in the font software to access the symbol glyphs.

The x-Binary-SignWriting is a 12-bit coded character set that does not directly encode the symbols of the ISWA 2010, but divides each symbol into a combination of 3 characters. The first character represents the base of the symbol. The next represents the fill of the symbol. The last character represents the rotation of the symbol.

4.1. Grapheme

The grapheme is the fundamental unit of writing for the SignWriting script. Many graphemes of SignWriting are visually iconic. The main writing graphemes of SignWriting represent a visual conception: either hands, movement, dynamics, timing, head, face, trunk, or limb. The body concept is a combination of trunk and limb. The specific size and shape of each grapheme is designed to balance and complement other graphemes.

The writing graphemes are extensive and specifically organized for written sign language and sign gestures. The writing graphemes do not include the specific graphemes of DanceWriting or the general graphemes of MovementWriting.

The writing graphemes are used in clusters. A cluster is a spatial grouping of graphemes written as a single unit. The graphemes can overlap and obscure graphemes underneath. A cluster can represents a sign of a sign language or a visual performance of a sign gesture.

Detailed location graphemes are separate from the main writing graphemes. Detailed location graphemes are used individually or sequentially. They represent isolated analysis that is written outside the cluster.

Punctuation graphemes are used when writing sentences. They are used individually, between clusters.

When written by hand, lines are drawn to form each grapheme. Different styles draw different types of lines: either for personal taste, speed, or quality. The main types of handwriting are formal, cursive, and shorthand. Formal handwriting, equivalent to block printing, includes defined lines for all grapheme features, specific palm facings for hand shapes, and detailed arrow heads and tails. Cursive handwriting is more fluid and less detailed. Handwriting for personal use can omit palm facings, generalize arrows, and other liberties of personal consumption. Shorthand is a further reduction of detail, written for speed. Shorthand is a memory aid to a written record and should be rewritten soon after the notes were taken.

Understanding the ratios of size and shape for the graphemes improves hand writing. SignWriting was an exclusively handwritten script for 7 years before publishing formalized the Block Printing model.

4.2. Symbol

There are 37,811 symbols, each with a unique ID. A symbol ID is a sequence of six formatted numbers of increasing detail. The first dashed number defines the category (11). The first two dashed numbers define the group (11-22). The first four dashed numbers define a base (11-22-333-44). The fifth number represents the fill (55). The sixth number represents the rotation (66). A symbol ID is a combination of base ID with a valid fill and a valid rotation. A symbol ID has the format "nn-nn-nnn-nn-nn-nn", where each "n" is a digit from 0 to 9.

The fill modifier can best be understood through the palm facing of the hand graphemes. The palm facing is based on planes. The SignWriting script uses two planes: the Front Wall (Frontal Plane) and the Floor (Transverse Plane). There are 6 palm facings. The first three palm facings are parallel with the Front Wall. The second three palm facings are parallel with the Floor. The reader can view the signer from different viewpoints (expressive or receptive) and can view the hands from different perspectives (front or top), but no matter what the viewpoint or perspective, the first three Fills represent the palm facing parallel to the Front Wall and the second three Fills represent the palm facing parallel to the Floor.

Fill Indicator Meaning
01 grapheme with white palm reader sees palm of hand parallel Front Wall
02 grapheme with half black palm reader sees side of hand parallel Front Wall
03 grapheme with black palm reader sees back of hand parallel Front Wall
04 grapheme with white palm and broken line reader sees palm of hand parallel Floor
05 grapheme with half black palm and broken line reader sees side of hand parallel Floor
06 grapheme with black palm and broken line reader sees palm of hand parallel Floor

The fill modifier is redefined for the movement arrows of category 2.

Fill Indicator Meaning
01 a grapheme with a black arrow head movement of the right hand
02 a grapheme with a white arrow head movement of the left hand
03 a grapheme with a thin, unconnected arrow head spatial overlapping of movement arrows for the left and right hands when they move as a unit
04 Irregular arrow stems building blocks for complex movement

The rest of the other bases use a fill modifier for grouping and visual organization that is meaningful only for a particular base symbol or small set.

The rotation modifier can best be understood through the hand symbols. The first 8 rotations progress 45 degrees counter clockwise. The last 8 rotations are a mirror of the first 8 and progress 45 degrees clockwise. Zero (0) degrees is understood to point to the top of the grapheme.

Rotation Direction Degrees from top
01 Counter Clockwise 0
02 Counter Clockwise 45
03 Counter Clockwise 90
04 Counter Clockwise 135
05 Counter Clockwise 180
06 Counter Clockwise 225
07 Counter Clockwise 270
08 Counter Clockwise 315
09 Clockwise 0
10 Clockwise 45
11 Clockwise 90
12 Clockwise 135
13 Clockwise 180
14 Clockwise 225
15 Clockwise 270
16 Clockwise 315

4.3. Hierarchy

The symbols of the ISWA 2010 are placed in a layered hierarchy for organization and access. There are 4 levels to the ISWA 2010 hierarchy: category, group, base, and symbol.

There are 7 categories. The first number of the symbol ID identifies the category. The first 5 categories contain writing symbols for use in clusters: 1) Hands, 2) Movement, 3) Dynamics & Timing, 4) Head & Face, and 5) Body. The Body category can be broken into 2 subcategories: 5.1) Trunk and 5.2) Limb.

The 6th category is Detailed Location that contains symbols used alone or in sequence, always outside the cluster. The 7th category is Punctuation that contains symbols used between clusters for text.

The 7 Categories of the ISWA 2010

Cat Purpose Name Description
1 Writing Hands Handshapes from over 40 Sign Languages are placed in 10 groups based on the numbers 1-10 in American Sign Language.
2 Writing Movement Contact symbols, small finger movements, straight arrows, curved arrows and circles are placed into 10 groups based on planes: The Front Wall Plane includes movement that is "parallel to the front wall" and the Floor Plane includes movement that is "parallel to the floor".
3 Writing Dynamics & Timing Dynamics Symbols are used to give the "feeling" or "tempo" to movement. They provide emphasis on a movement or expression, and combined with Punctuation Symbols become the equivalent to Exclamation Points. The Tension Symbol, combined with Contact Symbols, provides the feeling of "pressure", and combined with facial expressions can place emphasis or added feeling to an expression. Timing symbols are used to show alternating or simultaneous movement.
4 Writing Head & Face Starting with the head and then from the top of the face and moving down.
5 Writing Body Torso movement, shoulders, hips, and the limbs are used in Sign Languages as a part of grammar, especially when describing conversations between people, called Role Shifting, or making spatial comparisons between items on the left and items on the right.
6 Detailed Location Detailed Location Detailed Location symbols used are used alone or in sequence outside of the cluster. They may be useful for sorting large dictionaries, refining animation, simplifying translation between scripts and notation systems, and for detailed analysis of location sometimes needed in linguistic research.
7 Punctuation Punctuation Punctuation symbols are used when writing complete sentences or documents in SignWriting.

There are 30 groups. The first 2 dashed numbers in the symbol ID identify the group. The 30 groups can be divided into 3 sets of 10. The first ten are hands, category 1. The second ten are movements, category 2. The third ten are categories 3 thru 7. In order, 1 group for the Dynamics & Timing category, 1 for Head, 4 for Face, 1 for Trunk, 1 for Limb, 1 for Detailed Location, and 1 for Punctuation.

The 30 groups with symbol ID segment.

First Set Second Set Third Set
01-01 Index 02-01 Contact 03-01 Dynamics & Timing
01-02 Index Middle 02-02 Finger Movement 04-01 Head
01-03 Index Middle Thumb 02-03 Straight Wall Plane 04-02 Brow Eyes Eyegaze
01-04 Four Fingers 02-04 Straight Diagonal Plane 04-03 Cheeks Ears Nose Breath
01-05 Five Fingers 02-05 Straight Floor Plane 04-04 Mouth Lips
01-06 Baby Finger 02-06 Curves Parallel Wall Plane 04-05 Tongue Teeth Chin Neck
01-07 Ring Finger 02-07 Curves Hit Wall Plane 05-01 Trunk
01-08 Middle Finger 02-08 Curves Hit Floor Plane 05-02 Limbs
01-09 Index Thumb 02-09 Curves Parallel Floor Plane 06-01 Detailed Location
01-10 Thumb 02-10 Circles 07-01 Punctuation

There are 652 bases. The first 4 dashed numbers of a symbol ID identify the base. The 652 bases are divided between the 30 groups. For each group, there are less than 60 bases. The bases are often displayed in columns of 10.

Each base can have up to 96 symbols. All 6 dashed numbers of the symbol ID are required to identify a symbol. Each symbol is a combination of a base, fill, and rotation. The fill is identified by the 5th number of the symbol ID with possible values from 01 to 06. The rotation is identified by the 6th number of the symbol ID with possible values from 01 to 16.

4.4. Combined Character Sequence

Each symbol of the ISWA 2010 can be expressed with a combination of 3 characters. The first character represents the base of the symbol. The next character represents the fill of the symbol. The last character represents the rotation of the symbol.

There are three forms the fill and rotation can use to represent their value: a hexadecimal key, an x-Binary-SignWriting character, or an x-Character-SignWriting character.

The x-Binary-SignWriting coded character set uses a 12-bit encoding. Code points in this set use a "B+" prefix along with the 3 hexadecimal digits that represent the value.

The x-Character-SignWriting coded character set uses the Private Use Area of Unicode. These code points occur on plane 15. Code points in this set use a "U+" prefix along with the 5 hexadecimal digits that represent the value.

The fill value ranges from 1 to 6. The fill key is 1 less than the value and ranges from 0 to 5.

Fill Value Key x-Binary-SignWriting x-Character-SignWriting
1 0 B+110 U+FD810
2 1 B+111 U+FD812
3 2 B+112 U+FD812
4 3 B+113 U+FD813
5 4 B+114 U+FD814
6 5 B+115 U+FD815

The rotation value ranges from 1 to 16. The rotation key is written in hexadecimal and is equal to 1 less than the value and ranges from "0" to "f".

Rotation Value Key x-Binary-SignWriting x-Character-SignWriting
1 0 B+120 U+FD820
2 1 B+121 U+FD821
3 2 B+122 U+FD822
4 3 B+123 U+FD823
5 4 B+124 U+FD824
6 5 B+125 U+FD825
7 6 B+126 U+FD826
8 7 B+127 U+FD827
9 8 B+128 U+FD828
10 9 B+129 U+FD829
11 a B+12A U+FD82A
12 b B+12B U+FD82B
13 c B+12C U+FD82C
14 d B+12D U+FD82D
15 e B+12E U+FD82E
16 f B+12F U+FD82F

Further, a 16 bit symbol code from the x-ISWA-2010 exists for each of the valid combined character sequences. This relationship can be stated as (symbol code = ((base code - 256) * 96) + ((fill value - 1) * 16) + rotation value). The first symbol code is 1 and the last valid symbol code is 62,504.

The first symbol has an ID of "01-01-001-01-01-01" and a symbol code of 1.

  • Symbol code 1 = symbol key S10000 = B+130, B+110, B+120 = U+FD830, U+FD810, U+FD820.
  • Symbol code 1 = ( ( hexdec('100') - 256 ) * 96 ) + ( ( fill_value(1) - 1 ) * 16 ) + rotation_value(1).
  • Symbol code 1 = ( ( 256 - 256 ) * 96 ) + ( ( 1 - 1 ) * 16 ) + 1.
  • Symbol code 1 = ( 0 * 96 ) + ( 0 * 16 ) + 1.
  • Symbol code 1 = 1.

4.5. Validity

Although there are 6 possible fills and 16 possible rotations, not every combination of base, fill, and rotation is valid. Each base has a set of valid fills and a set of valid rotation. These validity sets contain one or more values from the defined range.

For each value, the inclusion in the validity set can be expressed with a value of "0" or "1". For fill values, lining up the digit from left to right, will result in a string 6 digits long. The value of the 6 digit number is 2 ^ (value -1).

Fill Value 1 2 3 4 5 6 Binary Power of 2
1 X 100000 1
2 X 010000 2
3 X 001000 4
4 X 000100 8
5 X 000010 16
6 X 000001 32

The value of any fill validity set is equal to the sum of the power of 2 for each fill value in the set. The empty set is invalid and has a sum of zero (0). The full set of all possible fills has a sum of 63.

Fill Set 1 2 3 4 5 6 Binary Power of 2
{} 000000 0
{1,2,3,4,5,6} X X X X X X 111111 63

Each base has a defined validity set for fills. The "Fills" column in the "Bases" section.

The rotation validity sets have a larger range than the fills. The possible rotation values range from 1 to 16. The power of 2 numbers are 16-bit.

Value Binary Power of 2
1 2^0 1
2 2^1 2
3 2^2 4
4 2^3 8
5 2^4 16
6 2^5 32
7 2^6 64
8 2^7 128
9 2^8 256
10 2^9 512
11 2^10 1024
12 2^11 2048
13 2^12 4096
14 2^13 8192
15 2^14 16384
16 2^15 32768

The value of a rotation validity set is the summation of the power of 2 numbers. The minimum summation is 1. The largest possible summation is 65,535 where all 16 rotations are valid.

Each base has a defined validity set for rotations. The "Rotations" column in the "Bases" section.

Interestingly enough, there are only 12 possible validity sets in the ISWA 2010.

Sum Binary Set
1 100000 {1}
2 010000 {2}
3 110000 {1, 2}
7 111000 {1, 2, 3}
15 111100 {1, 2, 3, 4}
31 111110 {1, 2, 3, 4, 5}
63 111111 {1, 2, 3, 4, 5, 6}
187 11011101 {1, 2, 4, 5, 6, 8}
255 11111111 {1, 2, 3, 4, 5, 6, 7, 8}
511 1111111110000000 {1, 2, 3, 4, 5, 6, 7, 8, 9}
48059 1101110111011101 {1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 16}
65535 1111111111111111 {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}

5. SignPuddle Standard

The SignPuddle Standard for SignWriting text is nearing a stable and fully functional version 1.

5.1. Licenses

5.1.1. Open Font License

Our font software is available under SIL's Open Font License.

5.1.2. Creative Commons

Our reference material is licensed under Creative Commons attribution, share alike (by-sa).

5.1.3. GPL

The current open source projects are licensed under the GPL 2 for MediaWiki and GPL 3 for the general software on Github. Any contributions to the open source code must agree to a possible relicense in the future under a BSD like license.

5.1.4. BSD

After the financial issues of the Center for Sutton Movement Writing have been addressed, the open source projects will relicensed under a more open and free BSD-like license, such as the MIT License.

5.2. Infrastructure

The status of the infrastructure was 63% on Nov 2nd, 2012. The latest status can be found online.

5.2.1. SignWriting Text Reference

The SignWriting Text Reference is a work in progress to be completed in 2013. The end point is a printed manual with a DVD of fonts, source code, and reference material. It is and will be freely available online.

The material is about 50% available.

5.2.2. International SignWriting Alphabet Fonts

The International SignWriting Alphabet 2010 (ISWA 2010) Font Reference is a product of the collaboration between SignWriting inventor, Valerie Sutton, and SignWriting encoder Stephen E Slevinski Jr. Special thanks to Adam Frost's excellent work on the SVG refinement and more.

The ISWA 2010 fonts have been stable since their initial release on October 20th, 2010.

Valerie Sutton

  • hand crafted and organized 30K plus individual glyphs
  • created a 2 dimension PNG of 3 colors for each
  • named each individual glyph with 6 degrees of significance
  • font name: ISWA 2010 Sutton

Steve Slevinski

  • counted and numbered the glyphs
  • created mathematical names
  • analyzed PNGs for line and fill
  • refactored glyphs - font name: ISWA 2010 PNG Standard
  • extended glyphs - font names: ISWA 2010 PNG Inverse, Shadow, Colorized
  • traced glyphs - font names: ISWA 2010 SVG Line Trace, Shaddow Trace, Smooth, and Angular
  • refactored and extended Adam's SVG work - font name: ISWA 2010 SVG Refinement

Adam Frost

  • manually traced each and every glyph that could not be automatically rotated
  • font name: ISWA 2010 SVG Refinement
  • physically performed and photographed every hand shape
  • font name: ISWA 2010 Hand Photo
  • consulted with Valerie in places of ambiguity
  • found the Facial Irregularity, documented in the ISWA 2010 Errata

5.2.3. SignWriting Icon Server

The SignWriting Icon Server create SVG and PNG images and queries data collections using an open API. The image creation is stable and fully implemented. The API is currently under construction with only an initial level of support. It is half of the client-server model of SignWriting Text.

The mathematical names of the 2-dimensional logographs are used to create the images. These logograms come in all shapes and sizes.

A prerelease is available on Github. A release candidate 1 will be prepared when the API has been completed.

5.2.4. SignWriting Icon Client

The SignWriting Icon Client is a proof of concept.

The plain text model defines characters and the structure of mathematically sized logographic strings. The rich text model defines styling using basic CSS rules for HTML or MediaWiki markup. The rich text model is quickly approaching a usable beta. CSS Text Layout

Easy layout using basic CSS rules. A working prototype is available online.

Use CSS to make SignWriting text behave more like logographic text. Basic CSS rules can create SignWriting rich text in all modern browsers. It will work with either plain HTML or MediaWiki Markup. It uses simple math for layout. It has center data points for selecting text to copy and for searching text on a page. It uses images for individual signs and punctuation. It makes SignWritng text act more like text.

The current working prototype uses 12 CSS rules: 4 that cover every cluster, 4 that cover the data string, and 4 custom layout values for each cluster.


  • position: relative;
  • background-repeat: no-repeat;
  • background-origin: content-box;
  • padding: 10px;

Data Span

  • display: table-cell;
  • vertical-align: middle;
  • font-size:0%;
  • height: inherit;


  • width: ?px
  • height: ?px
  • left: ?px
  • background-image: url(ht..

The width, height, and left values are easy to calculate using the character string. No need to access a database or wait for the image server.

The background-image must link to a SignWriting Icon Server. CSS rules will directly effect the '''url''' affecting the style of the rich text. Specify the looks of Headings 1 thru 6, bold, italic, or to indicate URL links. jQuery Font Engine

Transforming Unicode PUA into HTML Widgets for rich text. Development on the ASL Wikipedia Project. jQuery Editors

Allows for the editing of logograms with basic HTML using INPUT or TEXTAREA. Circular Cursor

Within a sign logogram, the symbols are placed freeform in a 2-dimensional pattern. The cursor surrounds the selected symbol. The cursor can exist in any of 8 positions as on the compass: top, top-right, right, bottom-right, bottom, bottom-left, left, and top-left. New symbols are added in line with the selected symbol and the cursor placement. Expanded Symbol Palette

The symbol palette is a 2-dimension grid of buttons. The top level reveals the symbol groups. Selecting a symbol group reveals the available base symbols. These symbols can be dragged into the sign editor. An alternate form could use the circular cursor and either 2-button presses ( base symbol inserted ), or 3-button presses (exact symbol inserted).

The ISWA 2010, or a customized subset, should be available on a 6 by 16 grid in full expanded mode. Smaller screen may want to use 3 or 6 columns and a choice of 5,6,8,10,16 rows. Keyboarding

The keyboarding system for SignWriting was designed by Richard Gleaves as part of SignWriter. Keyboarding had a steep learning curve, but was very responsive once learned properly.

2 key presses per base symbol. Then use any of 3 transformations: rotate, flop, variation (length). Tap each one as many times as needed. The circular cursor of SignWriter was a great idea for adding new symbols to a sign quickly. Fine tune adjustments will be available for exact symbol position. Tabbing between symbols or signs. The international keyboard set makes it impossible to have a single solution for every keyboard. Symbol Set Configuration

While the international standard uses every symbol of the ISWA 2010, specific languages may want to limit and reorder the symbol set used in their languages. A unified configuration file will standardize both the symbol palette presentation and the keyboard design. I can automate the symbol palette presentation from the SignPuddle Online data, but the keyboard design will have to be completed by someone with knowledge of the native language and access to the available keyboard. Testing Suite

QUnit testing suite with exhaustive range to regex testing.

5.3. Compatibility

SignPuddle Online, ASL Wikipedia Project, SignTyp, SignWriter Studio, the DELEGS Editor, and more.

5.3.1. SignPuddle Online

SignPuddle Online is the current home of the international community of online writers of the SignWriting Script. Online tools make it possible to create SignWriting dictionaries and documents directly on the web. Each collection is freely available as a small XML file. Dozens of sign languages from around the world are represented. Each language can have several collections of SignWriting.

5.3.2. Wikimedia Labs

SignWriting has an open project on Wikimedia Labs. The ASL Wikipedia Project is in full swing. The Libras Wikipedia Project may start soon.

In general, Wikimedia Labs creates virtual computers running Linux. They use a special tool called Puppet to configure the virtual servers. Wikimedia Labs allows you to create, manage, and analyze the virtual servers through a MediaWiki based application. Wikimedia Labs is deeply integrated but not always configured properly or documented.

Wikimedia Labs has created a project for SignWriting. I am a super user on Wikimedia Labs. I administer the SignWriting project. I can create virtual servers at will, each is called an instance. I have 2 instances running. The first is "ase10", the 10th server I created before I had everything properly configured and installed. I created "ase11" when I was trying to fix the catastrophic crash of the ASL Wikipedia. "ase11" is a basic server without MediaWiki or the SWMP.

For the public to view anything on Wikimedia Labs, you must use an IP from a limited pool. Each project has a limit of 0 IPs when it is first created. This number can be increased according to need.

I have 2 public IPs for SignWriting. The first is used by the ASL Wikipedia Project and points to "ase10". The second is currently used for the SignWriting Icon Server installation for Wikimedia projects.

There is no BZS virtual server running on Wikimedia Labs. This needs to be created by a skilled and experienced Linux administrator through the Wikimedia Labs environment. BZS is pointing to the SignWriting Icon Server on "ase11".

You do not need a public IP to start development on Wikimedia Labs, only to be viewed by the public.

5.3.3. SignTyp

This standard is being integrated with the SignTyp linguistic coding system developed by Rachel Channon through an NSF grant.

5.3.4. SignWriter Studio

SignWriter Studio is a Windows-only compatible application by Jonathan Duncan. It has an alternate symbol selection technique. According to Valerie Sutton, it illustrates a unique insight into the hand shapes of the ISWA.

Jonathan Duncan writes:

  • SignWriter Studio has 4 ways to get the basic symbol base, and 3 ways to modify the selected base.
  • 1) Select the base symbol from a complete list of base symbols organized in a tree view 2) Search for a hand symbol in hand search section by hand feature. 3) Select a symbol already present in the signbox. 4) Select a symbol from a Favorites section.
  • Then one of three chooser to define the fill and rotation will become available. 1)The hand chooser. 2)The arrow chooser. 3)The general chooser.
  • The Hand chooser is to quickly find the symbol for a certain, hand, plain(wall or floor), palm facing and rotation. The Hand Chooser also extends add a fourth palm facing to logically show all possible symbols in their most common uses. This chooser resembles the instruction manual explaining the use of hand shapes.
  • The Arrow Chooser is to quickly find arrows for a certain hand, plain(wall or floor) and rotation.This chooser resembles the instruction manual explaining the use of arrows.
  • The General Chooser is for symbols for which the two previous chooser do not work well and gives a grouped list of symbols for the base group.

5.3.5. DELEGS Online

The DELEGS Editor from the University of Hamburg and C1 WPS GmbH in Germany is designed for Deaf Education. It is a tool for writing translation texts between spoken and signed languages.

Spoken language text is used to display horizontal SignWriting Text from left to right. The spoken language can appear beneath the sign or it can be hidden.

6. Unicode Integration

SignWriting Text is integrated with Unicode in the Private Use Area. If you see these characters, it means you do not have the client side font engine.

6.1. Private Use Area Font Characters

The Unicode PUA is a simple shift of the x-Binary-SignWriting coded character set. Each code is increased by decimal value 1,038,080 which is FD700 in hex. A client side font engine written in JavaScript will transform the Unicode PUA into HTML widgets for rich text.

Characters x-Binary-SignWriting and x-Character-SignWriting

Name Token BSW Codepoint(s) Unicode PUA
Sequence Marker A B+100 U+FD800
SignBox Marker B B+101 U+FD801
Left Lane Marker L B+102 U+FD802
Middle Lane Marker M B+103 U+FD803
Right Lane Marker R B+104 U+FD804
Columns 1 thru 6 (fills) i B+110 - B+115 U+FD810 - U+FD815
Rows 1 thru 16 (rotations) o B+120 - B+12F U+FD820 - U+FD82F
SignWriting Grid Pages (base symbols) w, s, or P B+130 - B+3BB U+FD830 - U+FDABB
Negative Numbers: -250 thru -1 n B+706 - B+7FF U+FDE06 - U+FDEFF
Positive Numbers: 0 thru 249 n B+800 - B+8F9 U+FDF00 - U+FDFF9

6.2. Proposal

A shift of the 12 bit characters of x-Binary-SignWriting by 1D700 will use the range U+1D800 to U+1DFFF, using eight 8-bit rows of Unicode Plane 1 known as the the SMP: Supplementary Multilingual Plane. These rows occur inside an unassigned section of the Notational systems.

These are the characters being used by the community. The gap between the ISWA 2010 symbols and the number sections illustrates two truths. First, the entire Sutton MovementWriting family will be encoded. Second, it doesn't really matter where the numbers are placed, perhaps plane 14.

The number characters encode the ruler principle with characters. The ruler principle is built in automatically for scripts written sequentially in one dimension. The number characters are needed for 2-dimensional logograms, where the spatial relationship between symbols is explicitly stated with X,Y Cartesian coordinates. Number characters may be a useful concept for other scripts and notations to support 2-dimensional script processing.

The entire set of characters is used for a plain text model of a 2-dimension logographic script with freeform placement of symbols.

Future additions to the ISWA 2010 will include essential hand shapes and new mouth shapes. New characters will extend the SignWriting Text model with minimal complications.

Future proposals will include the rest of the Sutton MovementWriting System.

7. IANA Considerations


Conforms with RFC 2040.

The 3 coded character sets of x-ISWA-2010, x-Binary-SignWriting, and x-Character-SignWriting are a stable and documented standard that is openly available under the Open Font License and Creative Commons for the Internet Community.

No further changes are planned for the symbolset, the script encoding model, the coded character sets, the character encoding forms, or the client-server model of named logograms. This document is a statement of stability.

8. Security Considerations


9. References

Appendix A. Modern SignWriting

This Internet Draft is in complete agreement with the theory and example workbook released on January 12th, 2012 called Modern SignWriting.

Modern SignWriting has example text and concretely defines the processes available. It fully documented the symbol encoding. The query language is by far the most important aspect of this design. Modern SignWriting section 9 clearly illustrates the searching available and the associated regular expression technology. I discussed the model on the Regular Expressions Experts list of Linked In the end of 2011.

Modern SignWriting is now part of the SignWriting Text Reference and available in wiki form and PDF.

Entire sections of the Modern SignWriting document will be included in this I-D as progresses is made.

Appendix B. Cartesian SignWriting

Cartesian SignWriting is the name of a script encoding model for SignWriting Block Printing. The mathematical model is defined by the SignWriting Text Language. This language uses formal words to name terms, signs, and punctuation.

Formal structures of logographic sign are mixed with punctuation to form text. Each logographic sign is a 2-dimensional arrangement of symbols defined with cartesian coordinates.

Cartesian SignWriting is a heuristic model. The first prototypes were created in 2008. Through trial and error, the model was successively refactored to reduce the complexity and the computation cost of the implementations. The model has been optimized for common usage and processing.

B.1. Signbox

Cartesian SignWriting uses coordinate based symbol placement.

Each logographic sign exists on its own 2-dimensional canvas. Each point on the canvas is identified with an X and a Y coordinate. Each canvas has a defined center. Formal numbers range from -250 to 249. Informal number have no limit.

           Y Axis
             | -
X Axis       |
  -          |           +
             | +

Symbols are placed on the canvas with coordinates that represent the top-left of the symbol image.

B.2. Temporal Order

A term is a specialized sign that uses a sequential prefix before the 2-dimensional signbox.

A sequence is a list of writing symbols and/or detailed location symbols. A valid sequence must contain at least one symbol and can not contain punctuation. A sequence is an optional sign prefix used to define a temporal order.

The temporal order of a sign is distinct from the visual cluster. Neither structure can be dirived from the other automatically. It requires human intelligence to correctly create the sequence from the signbox contents.

There are several theories on the best way to structure a sequence. The most productive is based on the SignSpelling Sequence theory of Valerie Sutton. A sequence is structured as a series of starting handshapes followed by optional movements, transitional handshapes, movement, and end handshapes. Only symbols from category 1 (hands) and category 2 (movement) should be used in this first section. The last section of the sequence should contain symbols of dynamics & timing, head & face, or body: categories 3, 4, and 5.

Detailed location symbols from category 6 can be used in a sequence, but are rarely (if ever) needed for a sequence in general writing.

B.3. Logograph of Logographs

Cartesian SignWriting text uses a series of canvases, each with a unique coordinate space. A higher level coordinate space can be created to represent an entire panel of SignWriting Text. Either a column of vertical writing or a row of horizontal. The higher level coordinate space has an origin of (0,0). For columns, the panels share a common height. For rows, the panels share a common width.

             X Axis
    (0,0)     width
 Y  h |           
    e |           
 A  i |           
 x  g |           
 i  h |           
 s  t |

The mathematics of the panel is defined in Modern SignWriting, section 10.D Variant Display Form: Panel. The SignWriting Icon Server contains the functions required to convert a section of SignWriting Text into a series of panels. This can be useful for presentation.

The development of the rich text model defines a higher level logograph with manipulation of the DOM using CSS rules.

Appendix C. Theory of SignWriting Grammar and Encoding

Sign language is vastly different than spoken language. Instead of the sequential sounds of the voice, there is a 3 dimensional space with simultaneous action. The SignWriting Script creates 2-dimensional writing that is visually icon and full of featural information. This is true on the symbol level and on the sign level. A symbol represents phonemic information and is full of featural information to better understand the phonemes of the symbols. A sign is a 2-dimensional arrangement of symbols and is full of featural information to better understand the morphemes of the signs.

The 2 families of the SignWriting Script are Handwriting and Block Printing. The Handwriting family integrates with diacritic marks. The Block Printing family uses 2-dimensional placement with overlap and overlay.

Both of these families identify features in the writing they produce. Block Printing uses more features and Handwriting often uses less.

The Block Printing family is aimed at the needs of the reader and the publisher. The Block Printing family is ready to standardize with a fully developed model.

The Handwriting family is concerned with the needs of the writer. The purpose is not to recreate the iconic symbols of the International SignWriting alphabet exactly by hand, but the purpose is to enable the writer to quickly write notes on paper or chalkboard. Handwriting often drops features of the SignWriting Script for efficiency and speed. If too many features are dropped, the writing may loose it's clarity over time as the writer is distanced from the writing. This is common for Shorthand.

C.1. Logographic Sign

A sign is a variably-size logographic word. It is a 2-dimensional combination of symbols inside of a signbox with a tight bounding box and an explicit center.

C.2. Punctuation and Text

Punctuation separates signs into structured sentences. A punctuation symbol is always used alone and should not be used in a sign. Line breaks should not occur before punctuation.

C.3. Terms

A term is a logographic sign with an optional prefix. The prefix is a sequential list of symbols that identify temporal order and additional analysis. Terms are special signs that are above the standard noise of SignWriting Text. The query language of Formal SignWriting support searching for general signs with the letter "Q" and searching for terms with the letters "QT".

C.4. Lanes

When written vertically, SignWriting can use 3 different lanes: left, middle, and right. The middle lane is the default lane and punctuation is always used in the middle lane. No matter the lane, the center of a sign is aligned with the center of the lane.

For body weight shifts to one side or the other, the center of the cluster is aligned with a fixed horizontal offset from the middle lane into either the left or right lane.

The left and right lanes are used to represent body weight shifts and are represented by a horizontal offset from the middle lane. Body weight shifts are important to the grammar of sign languages, used for two different grammatical aspects: 1) role shifting during sign language storytelling, and 2) spatial comparisons of two items under discussion. One "role" or "item" is placed on the right side of the body (right lane), and the other on the left side of the body (left lane), and the weight shifts back and forth between the two, with the narrator in the middle (middle lane).

C.5. Modes

The most common writing mode is vertical.

Vertical Writing Mode

              <-- width / extent -->
                     top side/
                    start side
              +--------------------+                  A
              |  ----> Block flow  |                  |
              |                    |                  |                   
              |  | i b    T F      |                  |
  left side/  |  | n a    e l      |  right side/  height/
  head side   |  | l s    x o      |  foot side    measure
              |  V i e    t w      |                  |
              |    n               |                  |
              |    e               |                  |
              |                    |                  |
              +--------------------+                  V
                    bottom side/
                      end side

Figure 1

  • downward inline base
  • rightward block flow
  • vertical translate by word
  • variable dimensions of words
  • center of word aligns with the central baseline
  • variable over and under values from central baseline

The horizontal writing mode can loose or obfuscate important grammatical information, but is still useful, especially for translations with a spoken language.

Horizontal Writing Mode

   ----> inline base
   | B f      Text
   | l l      Flow
   | o o
   v c w

Figure 2

C.6. Layout

The SignPuddle Standard for SignWriting Text uses a freeform layout with cartesian coordinates for absolute positioning. Additional layout options are included and explored.

The main issue of layout is how the writer will use the system. The balance between complexity and usability from the writer's perspective is of primary importance.

The second issue of layout involve comparison. Signs can quickly be scanned for the symbols used; however, the relative position of the symbols require an analysis of the layout. The different layouts offer different approaches for evaluation.

The third issues of layout involves variability. There are two types of variability. The first, inter-personal variability, occurs when writers pick different symbols and different details. Inter-personal variability is part of the writing system that layout can not resolve. The second, intra-personal variability, occurs when writers use the same symbols, but in slightly different positions. With layout choices, it is possible to reduce the intra-personal variability, but this reduction may harm the writing system by imposing too many restrictions on the writer.

A fourth issues of layout involves elegance and beauty. Some may consider one type of layout to be superior to another based on subjective personal opinions. SignWriting is a unique script. The ultimate choice of layout should be based on the writer's experience, comparison, and variability.

C.6.1. Freeform

With freeform layout, the writer decides what symbols to use and the exact symbol position. The freeform layout offers the greatest flexibility for the writer and the greatest intra-personal variability.

Cartesian coordinates specify X and Y coordinates for the top, left of the symbol glyph. The coordinates of the symbols relate to the center of the canvas. The Cartesian Coordinate system is a more practical choices for computer processing because the equations of layout and comparison are eaiser. This is the current method for writing. The writer is presented with a canvas and positions each symbol independently.

Polar coordinates specify an angle and a distance from the center of the sign to the center of each symbol. Polar coordinates require the pythagorean therum and the slope equation for standard processing.

C.6.2. Restricted

It is possible to impose restrictions on symbol placement thereby limiting the intra-personal variability of sign spellings.

For generic restrictions, instead of allowing any coordinates, it may be possible to limit the options. For example, with polar coordinates, only allow specific angles and specific distances. This has not been evaluated.

For specific restrictions it may be possible to perform a statistical analysis of the symbols used to come up with a limited number of attachment points around each symbol and a small list of predefined distances between symbols. This information would be symbol specific and could greatly reduce the intra-personal variability if successfully implemented.

C.6.3. Non-form

Some would argue that the writer should not determine the form of a sign, but should input linguistic analysis and let the layout/font manager determine the best representation for the written sign. This would change the script from a writing system into computer aided design, requiring concepts that are not part of the script and are not part of the writer's thought processes. The idea would make for an interesting project, but it is not about encoding SignWriting.

C.7. Positioning

Any of the above layout options have two choices for positioning: absolute or relative.

C.7.1. Absolute

The absolute position of each symbol relates to the center of the sign. The freeform layout section above is defined using absolute positioning.

C.7.2. Relative

A relative position relates the symbol position according to other symbols. This could be defined with a tree structure or a more complicated linked list. One or more root symbols could initialize the sign and other symbols would build from the roots. The restricted layout of polar coordinates is defined above using relative positioning.

The viability and usability of relative positioning is unknown and has not been investigated.

Author's Address

Stephen E Slevinski Jr SignPuddle EMail: