Index: HDDefs.h
===================================================================
diff -u -r214c8f2c0bce8e14e8a46ea01221c11f16d75b52 -ra000b2f3853b15600868922976d6db1c22970184
--- HDDefs.h	(.../HDDefs.h)	(revision 214c8f2c0bce8e14e8a46ea01221c11f16d75b52)
+++ HDDefs.h	(.../HDDefs.h)	(revision a000b2f3853b15600868922976d6db1c22970184)
@@ -238,6 +238,23 @@
 typedef enum HD_Pre_Treatment_Prime_States HD_PRE_TREATMENT_PRIME_STATE_T;  ///< Type for HD pre-treatment prime sub-mode states enumeration
 
 /**@}*/
+
+/**
+ *  @addtogroup PreTreatmentRecirc
+ *  @{
+ */
+
+/// Enumeration of pre-treatment recirculate states.
+enum HD_Pre_Treatment_Recirc_States
+{
+    PRE_TREATMENT_RECIRC_STATE = 0,                                 ///< Pre-treatment recirculate state.
+    PRE_TREATMENT_RECIRC_STOPPED_STATE,                             ///< Pre-treatment recirculate stopped state.
+    NUM_OF_PRE_TREATMENT_RECIRC_STATES                              ///< Number of pre-treatment recirculate states.
+};
+///< Type for HD pre-treatment recirculate sub-mode states enumeration
+typedef enum HD_Pre_Treatment_Recirc_States HD_PRE_TREATMENT_RECIRC_STATE_T;
+
+/**@}*/
 
 /**
  *  @addtogroup HDTreatmentMode