This will prevent Mark from sending you messages, friend request or from viewing your profile. They will not be notified. Comments on discussion boards from them will be hidden by default.
Animals much like modern humans first appeared about 2.5 million years ago. But for countless generations they did not stand out from the myriad other organisms with which they shared their habitats.
Peter, I added this note in the Kindle iOS app, as I click to export my notes to Goodreads.