Use proper doxygen markup to mark deprecations
diff --git a/include/polarssl/md.h b/include/polarssl/md.h
index 3472f80..95da80b 100644
--- a/include/polarssl/md.h
+++ b/include/polarssl/md.h
@@ -204,7 +204,7 @@
  * \brief          Free the message-specific context of ctx. Freeing ctx itself
  *                 remains the responsibility of the caller.
  *
- * \note           Deprecated: Redirects to md_free()
+ * \deprecated     Use md_free() instead
  *
  * \param ctx      Free the message-specific context
  *