diff --git a/App/prisma/schema.prisma b/App/prisma/schema.prisma
index 8d58048..33a680d 100644
--- a/App/prisma/schema.prisma
+++ b/App/prisma/schema.prisma
@@ -517,6 +517,11 @@ model PurchaseOrder {
   // resolved amount is stored here. Null on legacy/pre-feature POs ⇒ no explicit
   // advance, so Accounts defaults to the full remaining balance. Set once at
   // approval and not edited afterwards (issue #92).
+  //
+  // NOTE (issue #91): this IS the "exact sum due for payment" for an ADVANCE/PART
+  // request. When the structured payment-request lane (payment-term enum +
+  // separate approval) is built, reuse this column for the requested amount
+  // rather than adding a parallel "exact sum" field.
   suggestedAdvancePayment Decimal? @db.Decimal(12, 2)
   piQuotationNo      String?
   piQuotationDate    DateTime?