Font Guidelines: Scoring Applications

Target platform capabilities

• Font features that are not available on all device/OS platforms must be avoided.
• Glyphs are only available to the application via a named font exposed through a simple text drawing and metrics API, e.g. HTML5 Canvas or SVG 1.1. If you can't access some font engine feature via these simple APIs, that feature isn't an appropriate way to solve a problem.
• Specifically, access to a glyphs low level geometry like control points is not required to use the standard.
• Metadata describing a font must be provided in a file using some generic easily parseable format.

Basic metrics

The font's em square (i.e. ascender + descender) should be

Line height for stacking numerals

For numerals that should be stacked, e.g. time signatures, figured bass, etc., the consuming application should specify line spacing explicitly (perhaps as part of a text style definition) rather than relying on the default line height of the font, which is much too large.

Stylistic alternates and ligatures

For applications that do not support advanced OpenType features, give ligatures and stylistic alternates explicit codepoints.