A new user looking for the first time at a pressure or head graph might be fooled by the fact that the Y axis does not mention that the units being graphed are in an absolute value. He or she might think hey I'm ok, minimum gauge value is 10 meters when in fact it is 0 meters.
Agree. We use four different surge software (one of them being Bentley Hammer) and it can be confusing when looking at Hammer results if the units are not explicitly stated so it can be as simple as labelling 'bar-g' and/or 'bar-a' to denote gauge vs absolute