Subtraction is the operator (hence the minus sign).
No one knows except for the owner of the name. It could mean anything.
Vpp is Peak-to-Peak voltage, in other words, in AC voltage, the peak-to-peak voltage is the potential difference between the lowest trough in the AC signal to the highest. Assuming the reference to...
It means the number 5 like v+7=12
Hugo Weaving plays V in "V for Vendeatta".