Example:
10 volts, high (of pressure), low (of temperature), category 3 (as used to rate the strength 'quality' of a storm), 3 MB (a file size), qualifications, grades.
Scope note:
Introduce subclasses of 'quality datum' in RDL to distinguish categories of data, such as nominal versus measured values.
Iof usage note:
Quantification may be on nominal, ordinal, and other scales.
This class may be used for data that don't fit the restriction to "single unit, single number" of 'scalar quantity datum', including data employing vectors instead of numbers, and conventional categories like "high" and "medium".
