[Ryan]

I know that Dolby Digital has set standards for the film industry.
-20dBFS = 0VU = 85SPL

Is it true when delivering final mixes (assuming the editor is laying
back to tape), there must be a -20dBFS 1kHz tone in the final mix
(whether digital or not) in order to calibrate the layback machine?

My follow up question is: Are there broadcast standards for audio?
I've heard that it depends on the station. Where can these be found?
And what's the general work flow in terms of delivering audio for
broadcasting?

Thanks in advance