Originally Posted by: LeedoggIs that a Hz measurement? Like 440Hz = Standard EADGBe?

Sorry, yeah.
It's just short speak for standard tuning.
440Hz is usually printed on tuners as the point where the guitar is actually in tune.
Like when the VU meter is dead center, you get a green light and the needle is pointing at 440.

Don't have a clue why but that's what I've always called it.