another try at a proposal for scaling

At the Team B meeting this morning, we discussed changing the focus of
the font proposals from scaling text to scaling all content. This is an
attempt to capture the author's responsibility as "don't get in the way
of the user agent scaling functionality":

L2 SC: Content that is visually rendered can be resized uniformly.

This would give us a place to hang failures related to using absolute
measures.

HTML/CSS sufficient techniques for this SC could include:
1.	Using measures which are either relative to the enclosing
container (%) or are relative to the current font (em).
2.	Specifying the class of font, using the default font, or
specifying the use of a specific font but allowing for a fallback which
is not a specific font.

Failures could include:
1.	Using measures which are based on a physical length (for
example: px, in, pt in CSS)
2.	Using raster encoded material (especially that which contains
text) without sufficient resolution to scale adequately.
3.	Specifying the use of a specific font without providing a
fallback which is not a specific font.
4.	Using serif based fonts which may get scaled to very small sizes

Because of the difficulties discussed in reflowing content when it is
scaled a lot, we will not propose a success criterion about reflowing
when content is scaled. Perhaps this could become an advisory technique.


Loretta Guarino Reid
lguarino@adobe.com
Adobe Systems, Acrobat Engineering