[Question] Include/Exclude semantics

[mcucchi9]

At point 6 of the README "Include/Exclude semantics" paragraph it is stated that

If the same field is present in both include and exclude, it should be included.

Does this mean that specifying only include=<field> and exclude=<field> is equivalent to specifying only include=<field>, so that all other fields should be excluded, or that all fields including should be included in the response?