In this question is the following diagram for a voltage booster intended for small battery powered devices
The TPS61200 spec says GND is control/logic ground and PGND is power ground but this isn't reflected in the symbols chosen in the diagram. I'm also puzzled why the link to earth is shown on GND rather than on PGND.
From this key it seems that various parts of the above circuit are to be tied to chassis ground and not to (say) digital/common/signal/control/logic ground.
Why specify chassis ground? Am I wrong in interpreting that as the metal part of an enclosure which is (usually) tied to earth through the mains electrical connection for safety purposes.
I have looked at similar questions here† but am still puzzled by the choice of symbols on the example circuit.
Why are these particular symbols used in this circuit diagram?
† Related questions