If you mean System V, that is public, but is different for each PLC. You are probably looking for a spreadsheet that lists (for example) what V7700 means in each in each CPU type, along with every other System V register. I don't know of any type document existing, but you may want to post this question on the AutomationDirect forum and another user like yourself may have one to share!
We have always addressed it from the perspective of "what do I want to do" => "how do I do it", e.g. to set up the analog pointer method of slot 3 in an 06, set the data address in System V register Vxxxx and the data format in register Vxxxy. I've never done the opposite "What does System V register Vxxxx do? What values does it take and what do they mean?".
A list like this would be quite helpful in understanding undocumented ladder logic. Some of the System V locations have System Nicknames, but those are only for the common System V registers that don't change from CPU to CPU, e.g. _ScanCounter.
If you get some helpful info on the ADC forum, please respond here with any goodies you discover over there!
