Rules of thumb for dimension mapping

When you choose the match mode to use for generating your dimension values, keep in mind the following two rules of thumb:

If you manually define dimension values in the dimension hierarchy, the Normal, Must Match, and Auto Generate features behave identically with respect to those dimension values.
Any source property value that does not have a matching dimension value specified in the dimension hierarchy will not be mapped unless you have set the dimension to Auto Generate in the pipeline.