Each fact in RM has a primary flag and a private flag.
RM's primary flag seems to impact only reports such as pedigree reports that inherently include only one fact of each type, and it selects the one fact of a given type which is to be displayed in such reports.
RM's private flag allows facts to be suppressed on narrative reports. The logic is sort of backwards to FTM. In RM you would flag all but one fact of a given type as private. Then the one not flagged as private would be the one that's printed. So think conceptually (but not actually) of having every single fact in your whole RM database flagged as private, and then conceptually (but not actually) unflag the one fact of each type that you do want displayed. In practice, you would only do this sort of thing for the cases where you have multiple and conflicting facts of the same type for a given individual.
RM does not have an equivalent facility for a primary name. All names are printed in a narrative report. I believe I have seen a message somewhere suggesting that RM8 will have such a facility for printing only primary names as an option, but I'm not sure about it and please don't hold me to it.