[mpeg-OTspec] OpenType 1.7 new "OS/2" size-range requires "name" table addition

[Adam Twardoch (List)]

"Charset" could be made a predefined parameter for one important reason: font fallback. 

For things like Noto or Source Han Sans and other such font collections, it would be easy to group fonts that cover various charsets, and the font selection mechanism could attempt font fallback within the same collection first, which would yield more consistent results. 

In a way, the predefined parameters echo the registered OT features like smcp, onum or liga — but for fonts. 

If we predefine Weight, Width and Slope, then supplemented with the already existing numerical params, fonts could be switched within a WWS context. 

If we predefine the OpSize parameter, then the new OS/2 optical size stuff is solved. And, as I said, predefining Charset would help in font fallback. 

And the custom name-value parameter pairs are a bit like named ssXX features: we don't really define the exact semantics but allow foundries to establish some still-common parameters as conventions, and still be flexible in things to come.