<region> (region) contains the name of an administrative unit such as a state, province, or
county, larger than a settlement, but smaller than a country. [14.2.3 Place Names]
<sch:rule context="tei:*[@calendar]"> <sch:assert test="string-length( normalize-space(.) ) gt 0"> @calendar indicates one or more systems or calendars to which the date represented by the content of this element
belongs, but this <sch:name/> element has no textual content.</sch:assert> </sch:rule>