Minor

Author: alexeysemenyukoracle

src/jdk.jpackage/share/man/jpackage.md

@@ -229,15 +229,15 @@ The `jpackage` tool will take as input a Java application and a Java run-time im
     substrings.
 
     Expandable substrings are case-sensitive on Unix and
-    case-insensitive on Windows. No string substitution occurs if the
+    case-insensitive on Windows. No string expansion occurs if the
     referenced environment variable is undefined.
 
     Environment variables with names "APPDIR", "BINDIR", and "ROOTDIR"
     will be ignored, and these expandable substrings will be
     replaced by values calculated by the app launcher.
 
     Prefix the dollar sign character with the backslash character (\)
-    to prevent substring substitution.
+    to prevent substring expansion.
 
 <a id="option-java-options">`--java-options` *options*</a>