I'm wondering whether the notBefore and notAfter date attributes can or should be used in combination with standardDate.
For example, if the date an author was born is uncertain, but is usually given as 306, does it make sense to use notBefore and notAfter to give the possible range, but also standardDate to give a single, machine-readable date that can be used for timelines, for instance?
<fromDate notBefore="0300" notAfter="0315" standardDate="0306">306</fromDate>
