How to set guidestripe?

What I want to do is use the “set guidestripe <num>” option in the ~/.nanorc but it doesn’t seem to be working because I encounter this message: "Unknown flag “guidestripe.” I can’t find any information on how to resolve this. Even when I try the command line arguments like “--guidestripe” or "--guidestripe=<number>” I get a "nano: unrecognized option” message.