Revising Document clearing primary content & attachments

Dear all,

I'm trying to figure out which is the best way to have WIndchill 10 to clear the document's primary content when revising: this to force user to upload an updated file on the new document revision rather than leave the "wrong" old one.

I've gone through most of the documentation but no hint about it.

Thinking it's a quite common requirement, I'm keen to find something on that as configuration or standard document behaviour.

Kind regards