The Track to Pad (TP) distance is specified in mm and is one of the parameters that determines the pattern class of the board.
A typical TP value is 0.150mm or 6mil. This is the value for our pattern class 6 our standard.
We define OTP as Outer layer Track to Pad distance and ITP as Inner layer Track to Pad distance.
Insulation is defined as
The insulation distance may not be reduced to less than 75% of the nominal distance (including unwanted random particles).
R1 > 0.75 A1
R2 + R3 > 0.75 A2