Some text for "Appendix: Best Practice Dependent Device Properties": I recommend this section at least reference the attributes of the core vocabulary to highlight to developers that these properties (at least) should be available in DDRs:

The following device properties included in the [DDR Core Vocabulary] are of particular value in supporting best practices recommended in this document, and should be available in any DDR supporting W3Cs DDR Core Vocabulary:

- Display Width, Display Height, Display Color Depth

- Input Devices

- Markup Support

- Stylesheet Support

- Image Format Support

- Input Mode Support

- Cookie Support

- Script Support

Best regards,

Bryan Sullivan | AT&T