diff --git a/doc/manual/source/replace.txt b/doc/manual/source/replace.txt
new file mode 100644
index 000000000..4cb2f2303
--- /dev/null
+++ b/doc/manual/source/replace.txt
@@ -0,0 +1,3 @@
+.. |ns3| replace:: *ns-3*
+
+.. |ns2| replace:: *ns-2*