"Summarizes the Tiered Taxes charged on this matter/invoice detailed in TAX_TIER_DETAIL by tx_id. There will be 0 or more TAX_TIER_SUMMARY segments per INVOICE segment. There will be 1 TAX_TIER_SUMMARY segment for each TAX.tx_id where TAX.'tax_tiers = ""Y"". Note that the EXTEND_HEADER option was purposely omitted from this segment. "