diff --git a/Adding-new-Module-types.md b/Adding-new-Module-types.md
index f259fa97..eb68c206 100644
--- a/Adding-new-Module-types.md
+++ b/Adding-new-Module-types.md
@@ -50,4 +50,6 @@ As of 3/9/17 (4.0.3) these functions are:
 * GPIO_HLW_CF1,        // HLW8012 CF1 voltage / current (Sonoff Pow)
 * GPIO_HLW_CF,         // HLW8012 CF power (Sonoff Pow)
 * GPIO_USER            // User configurable
-```
\ No newline at end of file
+```
+
+The user can only change GPIO functionality for pins that are defined as GPIO_USER in the module.
\ No newline at end of file