I would use the following sequence, in Stata terminology (I do not use SAS). First, in the male file, rename the mv* variables to be v*. Then append one file to the other. This is not a merge, it is an append. Then rename v001 to be hv001, v002 to be hv002, and v003 to be hvidx. Then sort the combined file on hv001, hv002, hvidx. Save with a temporary file name such as "IR_MR_temp.dta". Then open the PR file, NOT the HR file, and sort it by hv001, hv002, hvidx. Then merge with "IR_MR_temp.dta". Then save cases that are in both files. Good luck!