While working with Claire on the biblStruct elements we need to include in our document headers, I came up against a major problem with P5. Previous versions of P5 (including the one used to generate our Mariage project schema) included an element <dateRange>, which could be used to encode a range of dates when the precise date was not clear or unknown. However, <dateRange> has recently been removed from P5. A useful P4 alternative, the notBefore and notAfter attributes, has also been removed along with the from and to attributes, leaving <date> with only a dur attribute with a date type of xsd:duration to fill the gap.

The dur attribute is not intended for date ranges, and doesn't do the job. I wrote to the TEI list about this, and immediately got a phone call from Syd Bauman. After a long discussion, I wrote to the list again to propose that from, to, notBefore and notAfter be revived in P5, since they're clearly exactly what's needed in this case, and it's obviously not a boundary case. I hope we'll get them back. Meanwhile, Claire is using the precision="low" attribute/value to signal that a date is unsure (although Syd tells me precision is also gone, or going, from P5).