For parcels that weigh less than 20lbs but exceed 84 inches in combined dimensions, which pricing applies?

For parcels that weigh less than 20 pounds but exceed 84 inches in combined dimensions, the correct pricing that applies is Balloon Pricing. This pricing structure is designed to accommodate lightweight parcels with large dimensions, where the actual weight is not as significant as the size of the package. Balloon Pricing is beneficial because it allows the postal service to account for the space the package occupies in transportation and handling, rather than just its weight, thus ensuring fair pricing for items that are large but not particularly heavy.

In contrast, Flat Rate pricing is typically used for parcels that can fit into specific postal containers regardless of weight, as long as they do not exceed a weight limit. Dimensional pricing applies to larger, heavier packages that exceed certain dimensional limits but still indicates that the weight is a factor in determining cost. Standard weight pricing is generally used for regular packages that fall within certain weight limits without the same consideration for dimensions. Therefore, given the specific criteria of weight and size in the question, Balloon Pricing is the appropriate choice.