it would not have to be random. it could just be a sequence. the important thing is that you can recall the values that have generated and used. e.g. a data base table to query if a code had been generated and/or used and/or expired if there is a time limit for code use. However, I would use a GUID for this value.
Last edited by mmorgan30; July 2nd, 2016 at 12:08 AM.