diff --git a/src/FieldNames.cpp b/src/FieldNames.cpp
index e60d3d5de3..74d033c9ca 100644
--- a/src/FieldNames.cpp
+++ b/src/FieldNames.cpp
@@ -18,6 +18,7 @@ SField sfLedgerEntry(STI_LEDGERENTRY, 1, "LedgerEntry");
 SField sfTransaction(STI_TRANSACTION, 1, "Transaction");
 SField sfValidation(STI_VALIDATION, 1, "Validation");
 SField sfID(STI_HASH256, 257, "id");
+SField sfIndex(STI_HASH256, 258, "index");
 
 #define FIELD(name, type, index) SField sf##name(FIELD_CODE(STI_##type, index), STI_##type, index, #name);
 #define TYPE(name, type, index)
diff --git a/src/FieldNames.h b/src/FieldNames.h
index e1a72fa776..3a09f67a47 100644
--- a/src/FieldNames.h
+++ b/src/FieldNames.h
@@ -82,6 +82,7 @@ public:
 	bool isInvalid() const		{ return fieldCode == -1; }
 	bool isKnown() const		{ return fieldType != STI_UNKNOWN; }
 	bool isBinary() const		{ return fieldValue < 256; }
+	bool isDiscardable() const	{ return fieldValue > 256; }
 
 	bool operator==(const SField& f) const { return fieldCode == f.fieldCode; }
 	bool operator!=(const SField& f) const { return fieldCode != f.fieldCode; }