[MPEG-OTSPEC] "anim" feature tag

[Skef Iterum]

This is another proposal idea I can't do properly in the pre-April time 
frame, but it's short and simple.

Imagine you're a video editor working on a cable commercial about a new 
way to Make Lots of Money!!!  You overlay a row of dollar signs from a 
cool variable display font and animate them to "pulse" by changing their 
weight. Unfortunately, when you look at the result the number of slashes 
in each dollar sign keeps changing, greatly distracting your otherwise 
elegant and sophisticated effect.

The problem here is that doing the right thing for a given position in 
design space isn't always the right thing for animations that change the 
design space.

I think this distinction calls for a new registered feature tag, 
probably 'anim', that when active avoids, undoes, or compensates for any 
(or most) such abrupt adjustments. While this is something that could 
always just be thrown onto 'ss15' or whatever, it would be better to 
have a reserved name so that animation tools can leave that tag turned 
on by default.

A registered feature tag would also indicate something by its presence 
in a font: "we've thought about this problem". Designers might even 
throw it into a font with no such adjustments just to advertise that it 
is compatible with animation use.

This is a simple enough idea, but I lack the context to come up with 
specifically what the section needs to say -- what advice to give to 
designers. Someone closer to the design side of things would do a better 
job. If anyone comes up with that wording but doesn't want to worry 
about ISO header pages and such, send it to me and I'll wrap it up into 
a proposal.

Thanks,
Skef