DOC-6472 (#3963)

Author: RichardSmedley

modules/learn/pages/data/transactions.adoc

@@ -10,7 +10,8 @@
 
 == Overview
 
-Couchbase transactions support ACID properties for protected actions on the database.
+Couchbase transactions support ACID properties for protected actions on the database, within the same datacenter --
+for notes on transactions and cross-datacenter replication, see <<#transactions-and-replication-xdcr>>, below.
 
 *Atomicity* ensures that a transaction provides all-or-nothing semantics -- i.e.,  either all the documents modified in a transaction are committed, or none of the changes are committed. If there is a failure during transaction execution (such as the client crashing) all its changes are rolled back.