For an inclusive projection {type: 1}, I could replace 1 with NaN, "", "string", -1, which all work as an inclusive projection.
For an exclusive projection {type: 0}, I could replace 0 with false, null, undefined, which all work as an exclusive projection.
Is there documentation for the equivalent values?
I found this: https://github.com/mongodb/mongo/blob/master/src/mongo/db/query/projection_parser.cpp#L117
But not sure if that is the corresponding function, since it doesn't include strings.