diff --git a/extensions/drop-ins/README.TXT b/extensions/drop-ins/README.TXT
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+Developers:
+
+The Ant build file, Jskad/build.xml, looks in this directory for JARs.
+Any found are added to the classpath during an Ant run.  Example: put
+the JAR for a regexp library in here, and you can then change, say,
+org/thdl/tib/input/Jskad.java to use it, and your build will work
+fine.
+
+DC