diff --git a/appdx-segwit.asciidoc b/appdx-segwit.asciidoc
index 0a1a3019..0702f1e0 100644
--- a/appdx-segwit.asciidoc
+++ b/appdx-segwit.asciidoc
@@ -283,7 +283,7 @@ Eventually, however, almost all wallets will be able to support segwit payments.
 [[segwit_txid]]
 ===== Transaction identifiers
 
-One of the greatest benefits of Segregated Witness is that it eliminates third-party transaction malleability.
+((("transaction IDs (txid)")))One of the greatest benefits of Segregated Witness is that it eliminates third-party transaction malleability.
 
 Before segwit, transactions could have their signatures subtly modified by third parties, changing their transaction ID (hash) without changing any fundamental properties (inputs, outputs, amounts). This created opportunities for Denial-of-Service attacks as well as attacks against poorly written wallet software that assumed unconfirmed transaction-hashes were immutable.