When the restructures are unilateral and the club's option, that's a bad definition.
All the salary cap data I've seen is reported on a total dollars/season basis. None of it also tells you how many players are covered for those periods, much less how much can be restructured without requiring a negotiation with the player. Given how much variety there can be amongst 32 different organizations when it comes to handling such things, it's hard to get too worked up about a cap number until, pretty much literally, the week before VFA starts.
This year was the perfect storm in that regard for Dallas, with a franchise number on Spencer, the cap penalty, the restrictions placed by the newly negotiated CBA, and Tony Romo up for renewal...and I still don't know if we missed out on any players we'd have liked to have signed. Maybe we'd have been in the market for Clabo (probably) or a veteran Safety. But that's about it, as far as I can tell. Anybody else think of someone we might have wanted this offseason that we didn't go after? A backup RB, maybe?