Re: [dita] <data> use practice question: @value and content?

For a client I need to capture dates where the date as original authored
could be e.g. "Monday Dec 6, 2011". I need to retain the date as authored
but also need to capture a machine-processible date string, e.g., an ISO
date.

The date is metadata for the topic so I'm capturing it using <data> within
the topic prolog.

My initial instinct is to use the <data> content for the original string and
@value for the machine-processible date.

My question: is this use of both @value and direct content condoned by DITA?

I reviewed the reference entry for <data> and didn't see anything that
suggested one way or the other.

The alternative would be to have to two <data> instances, one for the
display date and one for the normalized date, but I was hoping to avoid that
since it's semantically the same date, just represented as two different but
equivalent strings.

Cheers,

E.