Clarification on the --region flag and the chr notation on vcf files

Hi!

I used "chr1" rather than "1" for --region option as an input since my vcf file has a chr notation. 
Do I also need to include "chr" notation for the genetic map file?

I used chr1 with a genetic map file having no chr notation but it still ran successfully, I just want to clarify if the genetic map file has been read correctly, otherwise, I'll put a chr notation in the gmap file. 

Thanks!