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The ductility-related force modification Factor Rd, and overstrength-related force modification factor Ro are input for both directions. The default values are from NBC Table 4.1.8.9: Ro = 1.7 and Rd = 3.0 for wood and 2.0 for gypsum wallboard. You are allowed to over-ride these to conform NBC to 4.1.8.9.(5) which allows Rd and Ro to be determined by tests and analysis, however in most cases the default values from table 4.1.8.9 should be used.
Shearwalls defines Rd and Ro for the entire structure, so that it does not implement 4.1.8.9.(4) allowing different Rd and Ro on each level.
It conforms to 4.1.8.9.(3) which calls for the lowest SRFS to be used on a level with combinations of SRFS, by detecting detects the presence of gypsum wallboard in a particular direction upon generating loads. If it is found, it warns you and offers to change the Rd value to the one corresponding to "all other materials". If you choose to use an Rd value for wood materials in the presence of GWB then the program automatically checks the Disable gypsum contribution design setting, so that the gypsum materials do not contribute to shear wall strength.
The default Ro values are the ones for wall that include gypsum wallboard panels, because the default standard walls include GWB.