-fd and -cr are deprecated parameters from earlier versions of the software.
-fd = File name DOS Expression (now -fed)
-cr = Containing text Regular Expression (now -cex)
-po is a flag that indicates if a value is found in the SRF file AND the command line the one from the command line should be used, e.g. to ensure the value *.txt is used for the file name when loading a SRF file:
FileLocatorPro.exe "C:\SavedSearch.srf" -f "*.txt" -po