[BlindMath] Thoughts on Markup Languages and Braille

[Susan Jolly]

Probably the people on this list know most of what is in this email but I 
thought it might be useful to put all this information in one place.

A typical markup language source file has two types of items.  One type is 
the text intended to be read by humans. The other type is instructions to an 
app that displays or renders the text to have the desired visual appearance; 
the instructions themselves aren't displayed.

HTML is a well-known example of a typical markup language with browsers 
being the apps that render HTML source.  LaTeX is another example of a 
markup language with many different apps that can display LaTeX source with 
attractive typesetting for both ordinary text and mathematics.

Braille is a special type of markup language in that its source file is 
intended to be read by humans. In other words, the instructions, known as 
braille indicators, are designed to be read along with the text rather than 
being instructions to a separate app.

Many markup language source files only use the 94 ASCII characters that 
appear on a standard keyboard. This means that the source files can be 
written and read directly by humans although this can be somewhat tedious so 
there are any number of systems designed to simplify writing source files 
for a particular markup language.

Microsoft Word is probably the best-known example of a What You See is What 
You Get app for generating markup source files.  Word uses a markup language 
known as Rich Text Format. When you enter text in Word or another WYSIWYG 
app you may not even realize that it is actually converting your text and 
your styling to a markup source file while at the same time displaying the 
styled text according to the hidden instructions.

Since braille source files are intended to be read by humans, the designers 
of braille systems have gone to a great deal of effort to make braille 
indicators as easy to read and write as possible. An example is the use of 
default indicator scopes to minimize the need for explicit end indicators. 
The single caps indicator automatically applies only to the next letter. The 
default for the italics word indicator is that it applies to the next 
sequence terminated by a space. Another example is using those braille cells 
with dots only in their right-hand columns as indicators.

Markup languages have made it possible for braille readers to access a great 
deal of information by reading markup source files directly using computer 
braille even though these source files are much more cluttered than the 
corresponding contracted literary braille or Nemeth braille math would be. 
They've also made it possible for screenreaders to present information in an 
audio rather than visual format.

Markup languages also make it possible to produce formatted text without the 
awkwardness of Word. Many sighted people prefer using markup languages for 
writing with new simpler ones frequently becoming available.  Markdown is 
currently popular as a simpler way of producing a subset of the text 
formatting instructions that be done with HTML. (Markdown apps actually 
convert markdown source to HTML source.)  A few years ago ASCIIMathML became 
a very popular way to enter math into a computer much more easily than 
entering either LaTeX source or MathML source.

HTH,
Susan J.