For my own enlightenment, I've been reading several lengthy treatises on the technical difference between the bang (!) operator and the dot (.) operator in MS Access. I understand the technical difference, and also see that in a majority of instances they can be used interchangeably.
My question to the community here - What is the accepted or preferred practice in usage of these two operators?

My current understanding is that "!" is preferred between user-defined collection and item names; and "." should be used prior to Microsoft Access defined property names. Also that square brackets, although not often required, are preferred around user-defined collection and item names.

What say the experts sitting around this campfire?