The Rod manufacturer can supply that info for you, so you can use their product correctly. Most name brands can be found on their websites and include recommended ranges of votage/currents etc.
John Wright

The AWS code system for identification of SMAW electrodes: Specification for Covered Electrodes, A5.1


For SMAW Rod (Electrode) The fourth or Fifth digit determine the flux coating (which in turn determines the polarity/s.)


Here is a link that demonstrates how the system works:
http://www.metroweld.com/faq.htm#3.%20What%20do%20the%20numbers%20on%20welding%20rod%20mean?

Try this site:
www.asminternational.org/pdf/bluebooklite.pdf