Each input title is processed in turn. Its list of field names is retrieved (in no particular order) and then [[dominantly appended|Dominant Append]] to the operator's output.
<<.from-version "5.1.22">> If the `include` suffix is used, fields are only included, if they exist. It doesn't matter, if fields have a value. The `exclude` suffix is there for convenience, since it would be possible to use a second filter run. For more info see the examples.