the earliest nerc tag application was based on a microsoft excel spreadsheet, and was introduced in 1997. the form was usually completed by the power marketers or schedulers, by defining the date and time of the transaction, the physical path of the energy schedule from its point of generation to point of consumption, the financial path (buying/selling chain) of the energy schedule, the hourly energy amounts scheduled to flow, and also the oasis transmission requests for each power system crossed which thereby documented that permission to cross each power system had been properly obtained.