||Is it possible to use more
user-defined characters than the number
of character codes available?
It is actually a mistake
to think that a character code must be given to a
character in order to specify that character.
With the HTML language, used for creating
documents on the Internet, and the SGML language,
famous for CALS, it is possible to specify
characters that have no character code by name,
instead of using the character code itself.
Of course, character codes are used to describe
the character's name.
For example, in the HTML language, the
"&" character has a special
meaning, making it impossible to use it directly
in a document. The & character has been given
the name amp; by following the rule that when
& appears in a document, it should be
considered to be the & character, it is
possible to use a character that cannot be
described with a character code by including the
name of the character instead.
In the same way, under the XKP standard there is
a method for describing characters using names.
They are recorded internally by the computer, not
with user-defined character codes, but as data in
the following form.
expressed as &00012345.
With this method, it is
possible to use a practically infinite number of
user-defined characters without using up even one
character in the user-defined character area.