What kind of Modbus map lacks 4xxxxx registers

What kind of Modbus does ABB's Totalflow flow meter have?

The explanation of the register maps is,

"Totalflow G4 devices provide access to application data by numeric tags. These numeric tags consist of three values – application number, array number and register number. These three values uniquely identify any accessible application data item. These values are commonly expressed as app.array.register." (pg 159 pdf, B-1)

How does one relate that to the battery voltage floating point value in register 3.5 (page B-36, pg 159 pdf) or DP live value in register 3.0?

ABB's Totalflow® XSeries G4 Flow Computer User’s Manual is here:

This isn't trivial. Appendix B, Modbus Register Maps starts on page 159 (of 362 pages) and continues to page 313, a total of 203 pages so the register map constitutes 56% of the entire manual, but has nary a 4xxxxx or 3xxxxx reference that I can find. How is the data accessed?