Radio
One choice from a short list, always in a group. Specification: docs/components/radio.md · shared anatomy: docs/components/choice.md
Group
Radios are always inside a fieldset.
Invalid and disabled
Orientation
data-orientation on the fieldset: horizontal or vertical. Without it, Canon stacks them.
Size
data-size on the fieldset or a container: a 16 / 20 / 24px circle.