The Free On-line Dictionary of Computing (30 December 2018):

VCC filtering

    A technique for reducing the amount of Radio
   Frequency Interference spread via power supply connections.
   VCC is a common name for the non-ground power supply line
   in circuits based on bipolar transistors.

   When part of a circuit generates lots of radio-frequency
   noise, that portion of the power plane can be isolated from
   the rest of the circuit and power delivered to it via a low
   pass filter, usually a PI filter, as shown in the diagram
   below.

         source   ________inductor_________   load
   		  |                |
   	      capacitor        capacitor
   		  |                |
   	       ground           ground

   This helps to shield the rest of the circuit from the noise
   generated by the load.

   (1998-01-26)