This issue concerns business rule development for Residual Zone Pricing. Residual Zone is an aggregate pricing point containing all load buses in the physical zone, less any load buses that has been designated to be priced at a specific non-zonal (nodal) location. Residual Zone Pricing is the use of this residual zone LMP instead of the physical zone LMP for pricing real-time load. Business rules are being developed concerning the election of residual zone pricing as well as the method of calculating residual zone aggregate definitions for use in the Day-ahead Energy Market, Real-time Energy Market, for FTRs and ARR modeling, and for reconciliation settlement.