I don't know whether this has been suggested before, google was my friend...
I've often seen newbies (and not-so-newbies, me included) resuscitating ancient threads.
Sometimes this is good and brings new valuable information, most of the times it just adds noise.
In many forums the original post date is shown, together with the last one: I think this could prevent some necroposting (or at least limit it).
Is this a possible option with this forum software? Are there reasons this is not done?