[...much deleted...]
> The no-break space disallows browsers from breaking a line at that point.
> The soft hyphen permits hyphenation of a word at that point but the s-h
> vanishes if it is not needed.
>
> The problem is that these characters are not available in
> all code sets. It's one thing to require support for characters
> like greater-than or less-than; the graphic characters in ASCII
> are available in nearly every code set and encoding method.
> However, if HTML mandates support for the no-break space and
> soft hyphen, it may be creating a problem in the future for
> those who use code sets that don't have these characters. [...]
Entities don't have to map to characters; they can be defined
as processing instructions or external data entities as well.
<!ENTITY shy PI "soft-hyphen">
­ would expand to the processing instruction <?soft-hyphen>
which the parser could interpret appropriately.
<!ENTITY nbsp SYSTEM "space.gif" NDATA GIF>
could be used to map to a GIF image. (Not terribly
useful for , but Bert Bos' proposed WWWicon entity
set could be defined this way.)
--Joe English
joe@trystero.art.com