<a:documentationxmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0">(formula) contains a mathematical or other formula. [14.2. Formulæ and Mathematical Expressions]</a:documentation>
<a:documentationxmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0">contains any single measurement forming part of a dimensional specification of some sort. []</a:documentation>