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+# zcl Extensions
+
+This directory contains some packages implementing some extensions to zcl
+that add features by building on the core API in the main zcl package.
+
+These serve as optional language extensions for use-cases that are limited only
+to specific callers. Generally these make the language more expressive at
+the expense of increased dynamic behavior that may be undesirable for
+applications that need to impose more rigid structure on configuration.