Re: TrueType, PUA and Windows

From: Erik van der Poel (
Date: Mon Nov 29 1999 - 16:40:26 EST

Cc'ing mozilla-mathml. This discussion started on the Unicode mailing
list. wrote:
> Erik:
> >So we are wondering whether it would be wise to use
> >Unicode-encoded TrueType fonts for math, and to use the PUA for
> >those symbols that end up being rejected by the Unicode
> >committee.
> Some questions:
> What is the expectation and intention as far as use?

I don't really know exactly what the STIX project intends to come up
with, but if other math fonts (e.g. Mathematica's) are any indication,
then they will presumably include whole glyphs at different sizes within
a single font (e.g. the square root thingie at various sizes) as well as
partial glyphs that are supposed to be glued together (e.g. top part,
straight part, middle part and bottom part of curly braces '{' and '}').

> Do you
> intend that people who want to present math in web pages should
> adopt a PUA encoding that you propose?

No, MathML has character entities like ⟸ which has
been assigned the PUA code U+E200. The idea is to use the entities
rather than the PUA codes in documents.

> Is this to be some kind of quasi-standard?

No, the specific PUA codes used by the MathML spec, Mozilla and any
fonts are supposed to be private agreements, not public standards.

> How would Mozilla deal with semantics for these PUA characters?

Well, the semantics of the character entities are clear. If Mozilla
detects fonts on the system that include the various math glyphs and
glyph parts, then it will map the document's characters and character
entities to font glyphs, not necessarily one-to-one. Mozilla needs to be
careful not to let any of the PUA codes "escape" out of the app, e.g.
cut/copy/paste, which will probably be done in terms of MathML "source",
including character entities, markup and all.


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