Thanks to ideas suggested in a useful comment thread at contract drafting guru Ken Adams’s blog, I added some return-or-destruction clauses to the Confidential information provisions, and tweaked some others. For example:
Deadline for destruction of system media: Any system-type media containing confidential information (for example, email backup tapes) that are not returned or destroyed when otherwise required by this Agreement must be overwritten or otherwise destroyed no later than three years after the termination of this Agreement.
Retention required by law: Confidential information need not be returned or destroyed to the extent that applicable law requires its retention.
Retention upon advice of counsel: Confidential information need not be returned or destroyed to the extent that the receiving party’s outside- or in-house counsel advises that it be retained for possible use in legal or administrative proceedings involving the receiving party.