]> Group ruby Extend the content model to allow group ruby. rbc: ruby base component Define complexTypes "rbc.content" and "rbc.attrib" to extend the content model and the attribute list of the rbc element respectively. rtc: ruby text component Define complexTypes "rtc.content" and "rtc.attrib" to extend the content model and the attribute list of the rtc element respectively. The rbspan attribute is added only when group ruby is used.