This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
unless i'm badly mistaken, an "implemented field" is to variables what an "instance method" is to a procedure / code snippet. that is, a variable that wouldn't be considered fully virtual, one that would be instantiated if the class were to be instantiated. i might be wrong, though.