In order to have a clean route, occasionally the designer may have to swap pins or gates on some devices. Usually the devices that require pin or gate swaps include resistor networks, capacitor networks, gated ICs (such as buffers), inverters, analog gates, and occasionally FPGAs.
In every case the designer must consult with the engineer and get permission to make any changes. After making any changes, the information must be fed back to the engineer in the form of a was/islist or back annotation directly to the schematic.
Pin swapping is when the individual pins of a single device are swapped. Typically this is done on resistor networks. Figure 53 is an example of swapping pins 4 and 5, and pins 3 and 6.