NONE
you don't have to know ANY drug dosages for step II or Step III !!!
however you are expected to know the route of administration of the meds, and the duration of treatment of certain meds,
for example you should know that high potency conventional antipsychotics (haldol) are useful as depot injections for noncompliant patients or can be given IM route for acute psychosis when patient is unable or unwilling to take PO.
An example of duration you should know is in cases of Depression treatment with SSRI's should be continued for 6 months following the first patient response.