This bug is related to the TEI P5 V0.9
The attibute "when" of the element "date"
<TEI><teiHeader><fileDesc><sourceDesc> <recordingStmt><recording rend="ES04.avi"
is defined in the RelaxNG schema but If I try to validate one XML with the DTD instead of the RelaxNG then I can't validate the document because I am using the "when" attribute and not is defined inside of the DTD.
I think that this is a mistake and inside of the DTD is needed to include this definitions.
Congratulations for the jobs !!!!
Jose Maria Alcaraz