Robust or operable?

[jkshapiro]

Section 4 of the document is titled "Mobile accessibility considerations related primarily to Principle 4: Robust". Isn't robustness about making sure that content can be interpreted by a variety of user agents?

These items—"Set the virtual keyboard to the type of data entry required", "Provide easy methods for data entry", and "Support the characteristic properties of the platform"—sound like they relate rather to Principle 2: Operable.